[PATCHv5 00/13] Integration of videobuf2 with dmabuf

[PATCHv5 00/13] Integration of videobuf2 with dmabuf

[Tomasz Stanislawski]

Hello everyone,
This patchset adds support for DMABUF [2] importing to V4L2 stack.
The support for DMABUF exporting was moved to separate patchset
due to dependency on patches for DMA mapping redesign by
Marek Szyprowski [4].

v5:
- removed change of importer/exporter behaviour
- fixes vb2_dc_pages_to_sgt basing on Laurent's hints
- changed pin/unpin words to lock/unlock in Doc

v4:
- rebased on mainline 3.4-rc2
- included missing importing support for s5p-fimc and s5p-tv
- added patch for changing map/unmap for importers
- fixes to Documentation part
- coding style fixes
- pairing {map/unmap}_dmabuf in vb2-core
- fixing variable types and semantic of arguments in videobufb2-dma-contig.c

v3:
- rebased on mainline 3.4-rc1
- split 'code refactor' patch to multiple smaller patches
- squashed fixes to Sumit's patches
- patchset is no longer dependant on 'DMA mapping redesign'
- separated path for handling IO and non-IO mappings
- add documentation for DMABUF importing to V4L
- removed all DMABUF exporter related code
- removed usage of dma_get_pages extension

v2:
- extended VIDIOC_EXPBUF argument from integer memoffset to struct
  v4l2_exportbuffer
- added patch that breaks DMABUF spec on (un)map_atachment callcacks but allows
  to work with existing implementation of DMABUF prime in DRM
- all dma-contig code refactoring patches were squashed
- bugfixes

v1: List of changes since [1].
- support for DMA api extension dma_get_pages, the function is used to retrieve
  pages used to create DMA mapping.
- small fixes/code cleanup to videobuf2
- added prepare and finish callbacks to vb2 allocators, it is used keep
  consistency between dma-cpu acess to the memory (by Marek Szyprowski)
- support for exporting of DMABUF buffer in V4L2 and Videobuf2, originated from
  [3].
- support for dma-buf exporting in vb2-dma-contig allocator
- support for DMABUF for s5p-tv and s5p-fimc (capture interface) drivers,
  originated from [3]
- changed handling for userptr buffers (by Marek Szyprowski, Andrzej
  Pietrasiewicz)
- let mmap method to use dma_mmap_writecombine call (by Marek Szyprowski)

[1] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/42966/focus=42968
[2] https://lkml.org/lkml/2011/12/26/29
[3] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/36354/focus=36355
[4] http://thread.gmane.org/gmane.linux.kernel.cross-arch/12819

Andrzej Pietrasiewicz (1):
  v4l: vb2-dma-contig: add support for scatterlist in userptr mode

Laurent Pinchart (2):
  v4l: vb2-dma-contig: Shorten vb2_dma_contig prefix to vb2_dc
  v4l: vb2-dma-contig: Reorder functions

Marek Szyprowski (2):
  v4l: vb2: add prepare/finish callbacks to allocators
  v4l: vb2-dma-contig: add prepare/finish to dma-contig allocator

Sumit Semwal (4):
  v4l: Add DMABUF as a memory type
  v4l: vb2: add support for shared buffer (dma_buf)
  v4l: vb: remove warnings about MEMORY_DMABUF
  v4l: vb2-dma-contig: add support for dma_buf importing

Tomasz Stanislawski (4):
  Documentation: media: description of DMABUF importing in V4L2
  v4l: vb2-dma-contig: Remove unneeded allocation context structure
  v4l: s5p-tv: mixer: support for dmabuf importing
  v4l: s5p-fimc: support for dmabuf importing

 Documentation/DocBook/media/v4l/compat.xml         |    4 +
 Documentation/DocBook/media/v4l/io.xml             |  179 +++++++
 .../DocBook/media/v4l/vidioc-create-bufs.xml       |    1 +
 Documentation/DocBook/media/v4l/vidioc-qbuf.xml    |   15 +
 Documentation/DocBook/media/v4l/vidioc-reqbufs.xml |   47 +-
 drivers/media/video/Kconfig                        |    1 +
 drivers/media/video/s5p-fimc/fimc-capture.c        |    2 +-
 drivers/media/video/s5p-tv/Kconfig                 |    1 +
 drivers/media/video/s5p-tv/mixer_video.c           |    2 +-
 drivers/media/video/videobuf-core.c                |    4 +
 drivers/media/video/videobuf2-core.c               |  207 ++++++++-
 drivers/media/video/videobuf2-dma-contig.c         |  529 +++++++++++++++++---
 include/linux/videodev2.h                          |    7 +
 include/media/videobuf2-core.h                     |   34 ++
 14 files changed, 932 insertions(+), 101 deletions(-)

-- 
1.7.5.4

[PATCHv5 01/13] v4l: Add DMABUF as a memory type

[Tomasz Stanislawski]

From: Sumit Semwal <sumit.semwal@ti.com>

Adds DMABUF memory type to v4l framework. Also adds the related file
descriptor in v4l2_plane and v4l2_buffer.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
   [original work in the PoC for buffer sharing]
Signed-off-by: Sumit Semwal <sumit.semwal@ti.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 include/linux/videodev2.h |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index c9c9a46..d884d4a 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -185,6 +185,7 @@ enum v4l2_memory {
 	V4L2_MEMORY_MMAP             = 1,
 	V4L2_MEMORY_USERPTR          = 2,
 	V4L2_MEMORY_OVERLAY          = 3,
+	V4L2_MEMORY_DMABUF           = 4,
 };
 
 /* see also http://vektor.theorem.ca/graphics/ycbcr/ */
@@ -588,6 +589,8 @@ struct v4l2_requestbuffers {
  *			should be passed to mmap() called on the video node)
  * @userptr:		when memory is V4L2_MEMORY_USERPTR, a userspace pointer
  *			pointing to this plane
+ * @fd:			when memory is V4L2_MEMORY_DMABUF, a userspace file
+ *			descriptor associated with this plane
  * @data_offset:	offset in the plane to the start of data; usually 0,
  *			unless there is a header in front of the data
  *
@@ -602,6 +605,7 @@ struct v4l2_plane {
 	union {
 		__u32		mem_offset;
 		unsigned long	userptr;
+		int		fd;
 	} m;
 	__u32			data_offset;
 	__u32			reserved[11];
@@ -624,6 +628,8 @@ struct v4l2_plane {
  *		(or a "cookie" that should be passed to mmap() as offset)
  * @userptr:	for non-multiplanar buffers with memory == V4L2_MEMORY_USERPTR;
  *		a userspace pointer pointing to this buffer
+ * @fd:		for non-multiplanar buffers with memory == V4L2_MEMORY_DMABUF;
+ *		a userspace file descriptor associated with this buffer
  * @planes:	for multiplanar buffers; userspace pointer to the array of plane
  *		info structs for this buffer
  * @length:	size in bytes of the buffer (NOT its payload) for single-plane
@@ -650,6 +656,7 @@ struct v4l2_buffer {
 		__u32           offset;
 		unsigned long   userptr;
 		struct v4l2_plane *planes;
+		int		fd;
 	} m;
 	__u32			length;
 	__u32			input;
-- 
1.7.5.4

[PATCHv5 02/13] Documentation: media: description of DMABUF importing in V4L2

[Tomasz Stanislawski]

This patch adds description and usage examples for importing
DMABUF file descriptor in V4L2.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 Documentation/DocBook/media/v4l/compat.xml         |    4 +
 Documentation/DocBook/media/v4l/io.xml             |  179 ++++++++++++++++++++
 .../DocBook/media/v4l/vidioc-create-bufs.xml       |    1 +
 Documentation/DocBook/media/v4l/vidioc-qbuf.xml    |   15 ++
 Documentation/DocBook/media/v4l/vidioc-reqbufs.xml |   47 +++---
 5 files changed, 224 insertions(+), 22 deletions(-)

diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml
index bce97c5..2a2083d 100644
--- a/Documentation/DocBook/media/v4l/compat.xml
+++ b/Documentation/DocBook/media/v4l/compat.xml
@@ -2523,6 +2523,10 @@ ioctls.</para>
         <listitem>
 	  <para>Selection API. <xref linkend="selection-api" /></para>
         </listitem>
+        <listitem>
+	  <para>Importing DMABUF file descriptors as a new IO method described
+	  in <xref linkend="dmabuf" />.</para>
+        </listitem>
       </itemizedlist>
     </section>
 
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml
index b815929..f8fb559 100644
--- a/Documentation/DocBook/media/v4l/io.xml
+++ b/Documentation/DocBook/media/v4l/io.xml
@@ -472,6 +472,162 @@ rest should be evident.</para>
       </footnote></para>
   </section>
 
+  <section id="dmabuf">
+    <title>Streaming I/O (DMA buffer importing)</title>
+
+    <note>
+      <title>Experimental</title>
+      <para>This is an <link linkend="experimental"> experimental </link>
+      interface and may change in the future.</para>
+    </note>
+
+<para>The DMABUF framework provides a generic mean for sharing buffers between
+ multiple devices. Device drivers that support DMABUF can export a DMA buffer
+to userspace as a file descriptor (known as the exporter role), import a DMA
+buffer from userspace using a file descriptor previously exported for a
+different or the same device (known as the importer role), or both. This
+section describes the DMABUF importer role API in V4L2.</para>
+
+<para>Input and output devices support the streaming I/O method when the
+<constant>V4L2_CAP_STREAMING</constant> flag in the
+<structfield>capabilities</structfield> field of &v4l2-capability; returned by
+the &VIDIOC-QUERYCAP; ioctl is set. Whether importing DMA buffers through
+DMABUF file descriptors is supported is determined by calling the
+&VIDIOC-REQBUFS; ioctl with the memory type set to
+<constant>V4L2_MEMORY_DMABUF</constant>.</para>
+
+    <para>This I/O method is dedicated for sharing DMA buffers between V4L and
+other APIs.  Buffers (planes) are allocated by a driver on behalf of the
+application, and exported to the application as file descriptors using an API
+specific to the allocator driver.  Only those file descriptor are exchanged,
+these files and meta-information are passed in &v4l2-buffer; (or in
+&v4l2-plane; in the multi-planar API case).  The driver must be switched into
+DMABUF I/O mode by calling the &VIDIOC-REQBUFS; with the desired buffer type.
+No buffers (planes) are allocated beforehand, consequently they are not indexed
+and cannot be queried like mapped buffers with the
+<constant>VIDIOC_QUERYBUF</constant> ioctl.</para>
+
+    <example>
+      <title>Initiating streaming I/O with DMABUF file descriptors</title>
+
+      <programlisting>
+&v4l2-requestbuffers; reqbuf;
+
+memset (&amp;reqbuf, 0, sizeof (reqbuf));
+reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+reqbuf.memory = V4L2_MEMORY_DMABUF;
+
+if (ioctl (fd, &VIDIOC-REQBUFS;, &amp;reqbuf) == -1) {
+	if (errno == EINVAL)
+		printf ("Video capturing or DMABUF streaming is not supported\n");
+	else
+		perror ("VIDIOC_REQBUFS");
+
+	exit (EXIT_FAILURE);
+}
+      </programlisting>
+    </example>
+
+    <para>Buffer (plane) file is passed on the fly with the &VIDIOC-QBUF;
+ioctl. In case of multiplanar buffers, every plane can be associated with a
+different DMABUF descriptor.Although buffers are commonly cycled, applications
+can pass different DMABUF descriptor at each <constant>VIDIOC_QBUF</constant>
+call.</para>
+
+    <example>
+      <title>Queueing DMABUF using single plane API</title>
+
+      <programlisting>
+int buffer_queue(int v4lfd, int index, int dmafd)
+{
+	&v4l2-buffer; buf;
+
+	memset(&amp;buf, 0, sizeof buf);
+	buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	buf.memory = V4L2_MEMORY_DMABUF;
+	buf.index = index;
+	buf.m.fd = dmafd;
+
+	if (ioctl (v4lfd, &VIDIOC-QBUF;, &amp;buf) == -1) {
+		perror ("VIDIOC_QBUF");
+		return -1;
+	}
+
+	return 0;
+}
+      </programlisting>
+    </example>
+
+    <example>
+      <title>Queueing DMABUF using multi plane API</title>
+
+      <programlisting>
+int buffer_queue_mp(int v4lfd, int index, int dmafd[], int n_planes)
+{
+	&v4l2-buffer; buf;
+	&v4l2-plane; planes[VIDEO_MAX_PLANES];
+	int i;
+
+	memset(&amp;buf, 0, sizeof buf);
+	buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+	buf.memory = V4L2_MEMORY_DMABUF;
+	buf.index = index;
+	buf.m.planes = planes;
+	buf.length = n_planes;
+
+	memset(&amp;planes, 0, sizeof planes);
+
+	for (i = 0; i &lt; n_planes; ++i)
+		buf.m.planes[i].m.fd = dmafd[i];
+
+	if (ioctl (v4lfd, &VIDIOC-QBUF;, &amp;buf) == -1) {
+		perror ("VIDIOC_QBUF");
+		return -1;
+	}
+
+	return 0;
+}
+      </programlisting>
+    </example>
+
+    <para>Filled or displayed buffers are dequeued with the
+&VIDIOC-DQBUF; ioctl. The driver can unlock the buffer at any
+time between the completion of the DMA and this ioctl. The memory is
+also unlocked when &VIDIOC-STREAMOFF; is called, &VIDIOC-REQBUFS;, or
+when the device is closed.</para>
+
+    <para>For capturing applications it is customary to enqueue a
+number of empty buffers, to start capturing and enter the read loop.
+Here the application waits until a filled buffer can be dequeued, and
+re-enqueues the buffer when the data is no longer needed. Output
+applications fill and enqueue buffers, when enough buffers are stacked
+up output is started. In the write loop, when the application
+runs out of free buffers it must wait until an empty buffer can be
+dequeued and reused. Two methods exist to suspend execution of the
+application until one or more buffers can be dequeued. By default
+<constant>VIDIOC_DQBUF</constant> blocks when no buffer is in the
+outgoing queue. When the <constant>O_NONBLOCK</constant> flag was
+given to the &func-open; function, <constant>VIDIOC_DQBUF</constant>
+returns immediately with an &EAGAIN; when no buffer is available. The
+&func-select; or &func-poll; function are always available.</para>
+
+    <para>To start and stop capturing or output applications call the
+&VIDIOC-STREAMON; and &VIDIOC-STREAMOFF; ioctls. Note that
+<constant>VIDIOC_STREAMOFF</constant> removes all buffers from both queues and
+unlocks all buffers as a side effect. Since there is no notion of doing
+anything "now" on a multitasking system, if an application needs to synchronize
+with another event it should examine the &v4l2-buffer;
+<structfield>timestamp</structfield> of captured buffers, or set the field
+before enqueuing buffers for output.</para>
+
+    <para>Drivers implementing DMABUF importing I/O must support the
+<constant>VIDIOC_REQBUFS</constant>, <constant>VIDIOC_QBUF</constant>,
+<constant>VIDIOC_DQBUF</constant>, <constant>VIDIOC_STREAMON</constant> and
+<constant>VIDIOC_STREAMOFF</constant> ioctl, the <function>select()</function>
+and <function>poll()</function> function.</para>
+
+  </section>
+
   <section id="async">
     <title>Asynchronous I/O</title>
 
@@ -671,6 +827,14 @@ memory, set by the application. See <xref linkend="userp" /> for details.
 	    <structname>v4l2_buffer</structname> structure.</entry>
 	  </row>
 	  <row>
+	    <entry></entry>
+	    <entry>int</entry>
+	    <entry><structfield>fd</structfield></entry>
+	    <entry>For the single-plane API and when
+<structfield>memory</structfield> is <constant>V4L2_MEMORY_DMABUF</constant> this
+is the file descriptor associated with a DMABUF buffer.</entry>
+	  </row>
+	  <row>
 	    <entry>__u32</entry>
 	    <entry><structfield>length</structfield></entry>
 	    <entry></entry>
@@ -746,6 +910,15 @@ should set this to 0.</entry>
 	      </entry>
 	  </row>
 	  <row>
+	    <entry></entry>
+	    <entry>int</entry>
+	    <entry><structfield>fd</structfield></entry>
+	    <entry>When the memory type in the containing &v4l2-buffer; is
+		<constant>V4L2_MEMORY_DMABUF</constant>, this is a file
+		descriptor associated with a DMABUF buffer, similar to the
+		<structfield>fd</structfield> field in &v4l2-buffer;.</entry>
+	  </row>
+	  <row>
 	    <entry>__u32</entry>
 	    <entry><structfield>data_offset</structfield></entry>
 	    <entry></entry>
@@ -980,6 +1153,12 @@ pointer</link> I/O.</entry>
 	    <entry>3</entry>
 	    <entry>[to do]</entry>
 	  </row>
+	  <row>
+	    <entry><constant>V4L2_MEMORY_DMABUF</constant></entry>
+	    <entry>2</entry>
+	    <entry>The buffer is used for <link linkend="dmabuf">DMA shared
+buffer</link> I/O.</entry>
+	  </row>
 	</tbody>
       </tgroup>
     </table>
diff --git a/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml b/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml
index 73ae8a6..adc92be 100644
--- a/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml
@@ -98,6 +98,7 @@ information.</para>
 	    <entry><structfield>memory</structfield></entry>
 	    <entry>Applications set this field to
 <constant>V4L2_MEMORY_MMAP</constant> or
+<constant>V4L2_MEMORY_DMABUF</constant> or
 <constant>V4L2_MEMORY_USERPTR</constant>.</entry>
 	  </row>
 	  <row>
diff --git a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml
index 9caa49a..cb5f5ff 100644
--- a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml
@@ -112,6 +112,21 @@ they cannot be swapped out to disk. Buffers remain locked until
 dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is
 called, or until the device is closed.</para>
 
+    <para>To enqueue a <link linkend="dmabuf">DMABUF</link> buffer applications
+set the <structfield>memory</structfield> field to
+<constant>V4L2_MEMORY_DMABUF</constant> and the <structfield>m.fd</structfield>
+to a file descriptor associated with a DMABUF buffer. When the multi-planar API is
+used and <structfield>m.fd</structfield> of the passed array of &v4l2-plane;
+have to be used instead. When <constant>VIDIOC_QBUF</constant> is called with a
+pointer to this structure the driver sets the
+<constant>V4L2_BUF_FLAG_QUEUED</constant> flag and clears the
+<constant>V4L2_BUF_FLAG_MAPPED</constant> and
+<constant>V4L2_BUF_FLAG_DONE</constant> flags in the
+<structfield>flags</structfield> field, or it returns an error code.  This
+ioctl locks the buffer. Buffers remain locked until dequeued,
+until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is called, or until the
+device is closed.</para>
+
     <para>Applications call the <constant>VIDIOC_DQBUF</constant>
 ioctl to dequeue a filled (capturing) or displayed (output) buffer
 from the driver's outgoing queue. They just set the
diff --git a/Documentation/DocBook/media/v4l/vidioc-reqbufs.xml b/Documentation/DocBook/media/v4l/vidioc-reqbufs.xml
index 7be4b1d..e3e709b 100644
--- a/Documentation/DocBook/media/v4l/vidioc-reqbufs.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-reqbufs.xml
@@ -48,28 +48,30 @@
   <refsect1>
     <title>Description</title>
 
-    <para>This ioctl is used to initiate <link linkend="mmap">memory
-mapped</link> or <link linkend="userp">user pointer</link>
-I/O. Memory mapped buffers are located in device memory and must be
-allocated with this ioctl before they can be mapped into the
-application's address space. User buffers are allocated by
-applications themselves, and this ioctl is merely used to switch the
-driver into user pointer I/O mode and to setup some internal structures.</para>
+<para>This ioctl is used to initiate <link linkend="mmap">memory mapped</link>,
+<link linkend="userp">user pointer</link> or <link
+linkend="dmabuf">DMABUF</link> based I/O.  Memory mapped buffers are located in
+device memory and must be allocated with this ioctl before they can be mapped
+into the application's address space. User buffers are allocated by
+applications themselves, and this ioctl is merely used to switch the driver
+into user pointer I/O mode and to setup some internal structures.
+Similarly, DMABUF buffers are allocated by applications through a device
+driver, and this ioctl only configures the driver into DMABUF I/O mode without
+performing any direct allocation.</para>
 
-    <para>To allocate device buffers applications initialize all
-fields of the <structname>v4l2_requestbuffers</structname> structure.
-They set the <structfield>type</structfield> field to the respective
-stream or buffer type, the <structfield>count</structfield> field to
-the desired number of buffers, <structfield>memory</structfield>
-must be set to the requested I/O method and the <structfield>reserved</structfield> array
-must be zeroed. When the ioctl
-is called with a pointer to this structure the driver will attempt to allocate
-the requested number of buffers and it stores the actual number
-allocated in the <structfield>count</structfield> field. It can be
-smaller than the number requested, even zero, when the driver runs out
-of free memory. A larger number is also possible when the driver requires
-more buffers to function correctly. For example video output requires at least two buffers,
-one displayed and one filled by the application.</para>
+    <para>To allocate device buffers applications initialize all fields of the
+<structname>v4l2_requestbuffers</structname> structure.  They set the
+<structfield>type</structfield> field to the respective stream or buffer type,
+the <structfield>count</structfield> field to the desired number of buffers,
+<structfield>memory</structfield> must be set to the requested I/O method and
+the <structfield>reserved</structfield> array must be zeroed. When the ioctl is
+called with a pointer to this structure the driver will attempt to allocate the
+requested number of buffers and it stores the actual number allocated in the
+<structfield>count</structfield> field. It can be smaller than the number
+requested, even zero, when the driver runs out of free memory. A larger number
+is also possible when the driver requires more buffers to function correctly.
+For example video output requires at least two buffers, one displayed and one
+filled by the application.</para>
     <para>When the I/O method is not supported the ioctl
 returns an &EINVAL;.</para>
 
@@ -102,7 +104,8 @@ as the &v4l2-format; <structfield>type</structfield> field. See <xref
 	    <entry>&v4l2-memory;</entry>
 	    <entry><structfield>memory</structfield></entry>
 	    <entry>Applications set this field to
-<constant>V4L2_MEMORY_MMAP</constant> or
+<constant>V4L2_MEMORY_MMAP</constant>,
+<constant>V4L2_MEMORY_DMABUF</constant> or
 <constant>V4L2_MEMORY_USERPTR</constant>.</entry>
 	  </row>
 	  <row>
-- 
1.7.5.4

[PATCHv5 03/13] v4l: vb2: add support for shared buffer (dma_buf)

[Tomasz Stanislawski]

From: Sumit Semwal <sumit.semwal@ti.com>

This patch adds support for DMABUF memory type in videobuf2. It calls relevant
APIs of dma_buf for v4l reqbuf / qbuf / dqbuf operations.

For this version, the support is for videobuf2 as a user of the shared buffer;
so the allocation of the buffer is done outside of V4L2. [A sample allocator of
dma-buf shared buffer is given at [1]]

[1]: Rob Clark's DRM:
   https://github.com/robclark/kernel-omap4/commits/drmplane-dmabuf

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
   [original work in the PoC for buffer sharing]
Signed-off-by: Sumit Semwal <sumit.semwal@ti.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/videobuf2-core.c |  196 +++++++++++++++++++++++++++++++++-
 include/media/videobuf2-core.h       |   27 +++++
 2 files changed, 219 insertions(+), 4 deletions(-)

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index 2e8f1df..d26b1cc 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -106,6 +106,36 @@ static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 }
 
 /**
+ * __vb2_plane_dmabuf_put() - release memory associated with
+ * a DMABUF shared plane
+ */
+static void __vb2_plane_dmabuf_put(struct vb2_queue *q, struct vb2_plane *p)
+{
+	if (!p->mem_priv)
+		return;
+
+	if (p->dbuf_mapped)
+		call_memop(q, unmap_dmabuf, p->mem_priv);
+
+	call_memop(q, detach_dmabuf, p->mem_priv);
+	dma_buf_put(p->dbuf);
+	memset(p, 0, sizeof *p);
+}
+
+/**
+ * __vb2_buf_dmabuf_put() - release memory associated with
+ * a DMABUF shared buffer
+ */
+static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+	unsigned int plane;
+
+	for (plane = 0; plane < vb->num_planes; ++plane)
+		__vb2_plane_dmabuf_put(q, &vb->planes[plane]);
+}
+
+/**
  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
  * every buffer on the queue
  */
@@ -227,6 +257,8 @@ static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 		/* Free MMAP buffers or release USERPTR buffers */
 		if (q->memory == V4L2_MEMORY_MMAP)
 			__vb2_buf_mem_free(vb);
+		else if (q->memory == V4L2_MEMORY_DMABUF)
+			__vb2_buf_dmabuf_put(vb);
 		else
 			__vb2_buf_userptr_put(vb);
 	}
@@ -349,6 +381,12 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
 		 */
 		memcpy(b->m.planes, vb->v4l2_planes,
 			b->length * sizeof(struct v4l2_plane));
+
+		if (q->memory == V4L2_MEMORY_DMABUF) {
+			unsigned int plane;
+			for (plane = 0; plane < vb->num_planes; ++plane)
+				b->m.planes[plane].m.fd = 0;
+		}
 	} else {
 		/*
 		 * We use length and offset in v4l2_planes array even for
@@ -360,6 +398,8 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
 			b->m.offset = vb->v4l2_planes[0].m.mem_offset;
 		else if (q->memory == V4L2_MEMORY_USERPTR)
 			b->m.userptr = vb->v4l2_planes[0].m.userptr;
+		else if (q->memory == V4L2_MEMORY_DMABUF)
+			b->m.fd = 0;
 	}
 
 	/*
@@ -451,6 +491,20 @@ static int __verify_mmap_ops(struct vb2_queue *q)
 }
 
 /**
+ * __verify_dmabuf_ops() - verify that all memory operations required for
+ * DMABUF queue type have been provided
+ */
+static int __verify_dmabuf_ops(struct vb2_queue *q)
+{
+	if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
+	    !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
+	    !q->mem_ops->unmap_dmabuf)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
  * vb2_reqbufs() - Initiate streaming
  * @q:		videobuf2 queue
  * @req:	struct passed from userspace to vidioc_reqbufs handler in driver
@@ -483,8 +537,9 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
 		return -EBUSY;
 	}
 
-	if (req->memory != V4L2_MEMORY_MMAP
-			&& req->memory != V4L2_MEMORY_USERPTR) {
+	if (req->memory != V4L2_MEMORY_MMAP &&
+	    req->memory != V4L2_MEMORY_DMABUF &&
+	    req->memory != V4L2_MEMORY_USERPTR) {
 		dprintk(1, "reqbufs: unsupported memory type\n");
 		return -EINVAL;
 	}
@@ -513,6 +568,11 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
 		return -EINVAL;
 	}
 
+	if (req->memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
+		dprintk(1, "reqbufs: DMABUF for current setup unsupported\n");
+		return -EINVAL;
+	}
+
 	if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
 		/*
 		 * We already have buffers allocated, so first check if they
@@ -619,8 +679,9 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 		return -EBUSY;
 	}
 
-	if (create->memory != V4L2_MEMORY_MMAP
-			&& create->memory != V4L2_MEMORY_USERPTR) {
+	if (create->memory != V4L2_MEMORY_MMAP &&
+	    create->memory != V4L2_MEMORY_USERPTR &&
+	    create->memory != V4L2_MEMORY_DMABUF) {
 		dprintk(1, "%s(): unsupported memory type\n", __func__);
 		return -EINVAL;
 	}
@@ -644,6 +705,11 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 		return -EINVAL;
 	}
 
+	if (create->memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
+		dprintk(1, "%s(): DMABUF for current setup unsupported\n", __func__);
+		return -EINVAL;
+	}
+
 	if (q->num_buffers == VIDEO_MAX_FRAME) {
 		dprintk(1, "%s(): maximum number of buffers already allocated\n",
 			__func__);
@@ -839,6 +905,14 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
 					b->m.planes[plane].length;
 			}
 		}
+		if (b->memory == V4L2_MEMORY_DMABUF) {
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				v4l2_planes[plane].bytesused =
+					b->m.planes[plane].bytesused;
+				v4l2_planes[plane].m.fd =
+					b->m.planes[plane].m.fd;
+			}
+		}
 	} else {
 		/*
 		 * Single-planar buffers do not use planes array,
@@ -853,6 +927,10 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
 			v4l2_planes[0].m.userptr = b->m.userptr;
 			v4l2_planes[0].length = b->length;
 		}
+
+		if (b->memory == V4L2_MEMORY_DMABUF)
+			v4l2_planes[0].m.fd = b->m.fd;
+
 	}
 
 	vb->v4l2_buf.field = b->field;
@@ -957,6 +1035,100 @@ static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 }
 
 /**
+ * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
+ */
+static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
+{
+	struct v4l2_plane planes[VIDEO_MAX_PLANES];
+	struct vb2_queue *q = vb->vb2_queue;
+	void *mem_priv;
+	unsigned int plane;
+	int ret;
+	int write = !V4L2_TYPE_IS_OUTPUT(q->type);
+
+	/* Verify and copy relevant information provided by the userspace */
+	ret = __fill_vb2_buffer(vb, b, planes);
+	if (ret)
+		return ret;
+
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
+
+		if (IS_ERR_OR_NULL(dbuf)) {
+			dprintk(1, "qbuf: invalid dmabuf fd for "
+				"plane %d\n", plane);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		/* Skip the plane if already verified */
+		if (dbuf == vb->planes[plane].dbuf) {
+			planes[plane].length = dbuf->size;
+			dma_buf_put(dbuf);
+			continue;
+		}
+
+		dprintk(3, "qbuf: buffer description for plane %d changed, "
+			"reattaching dma buf\n", plane);
+
+		/* Release previously acquired memory if present */
+		__vb2_plane_dmabuf_put(q, &vb->planes[plane]);
+
+		/* Acquire each plane's memory */
+		mem_priv = call_memop(q, attach_dmabuf, q->alloc_ctx[plane],
+			dbuf, q->plane_sizes[plane], write);
+		if (IS_ERR(mem_priv)) {
+			dprintk(1, "qbuf: failed acquiring dmabuf "
+				"memory for plane %d\n", plane);
+			ret = PTR_ERR(mem_priv);
+			goto err;
+		}
+
+		planes[plane].length = dbuf->size;
+		vb->planes[plane].dbuf = dbuf;
+		vb->planes[plane].mem_priv = mem_priv;
+	}
+
+	/* TODO: This pins the buffer(s) with  dma_buf_map_attachment()).. but
+	 * really we want to do this just before the DMA, not while queueing
+	 * the buffer(s)..
+	 */
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		ret = call_memop(q, map_dmabuf, vb->planes[plane].mem_priv);
+		if (ret) {
+			dprintk(1, "qbuf: failed mapping dmabuf "
+				"memory for plane %d\n", plane);
+			goto err;
+		}
+		vb->planes[plane].dbuf_mapped = 1;
+	}
+
+	/*
+	 * Call driver-specific initialization on the newly acquired buffer,
+	 * if provided.
+	 */
+	ret = call_qop(q, buf_init, vb);
+	if (ret) {
+		dprintk(1, "qbuf: buffer initialization failed\n");
+		goto err;
+	}
+
+	/*
+	 * Now that everything is in order, copy relevant information
+	 * provided by userspace.
+	 */
+	for (plane = 0; plane < vb->num_planes; ++plane)
+		vb->v4l2_planes[plane] = planes[plane];
+
+	return 0;
+err:
+	/* In case of errors, release planes that were already acquired */
+	__vb2_buf_dmabuf_put(vb);
+
+	return ret;
+}
+
+/**
  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
  */
 static void __enqueue_in_driver(struct vb2_buffer *vb)
@@ -980,6 +1152,9 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	case V4L2_MEMORY_USERPTR:
 		ret = __qbuf_userptr(vb, b);
 		break;
+	case V4L2_MEMORY_DMABUF:
+		ret = __qbuf_dmabuf(vb, b);
+		break;
 	default:
 		WARN(1, "Invalid queue type\n");
 		ret = -EINVAL;
@@ -1335,6 +1510,19 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
 		return ret;
 	}
 
+	/* TODO: this unpins the buffer(dma_buf_unmap_attachment()).. but
+	 * really we want to do this just after DMA, not when the
+	 * buffer is dequeued..
+	 */
+	if (q->memory == V4L2_MEMORY_DMABUF) {
+		unsigned int i;
+
+		for (i = 0; i < vb->num_planes; ++i) {
+			call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv);
+			vb->planes[i].dbuf_mapped = 0;
+		}
+	}
+
 	switch (vb->state) {
 	case VB2_BUF_STATE_DONE:
 		dprintk(3, "dqbuf: Returning done buffer\n");
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index a15d1f1..859bbaf 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -16,6 +16,7 @@
 #include <linux/mutex.h>
 #include <linux/poll.h>
 #include <linux/videodev2.h>
+#include <linux/dma-buf.h>
 
 struct vb2_alloc_ctx;
 struct vb2_fileio_data;
@@ -41,6 +42,20 @@ struct vb2_fileio_data;
  *		 argument to other ops in this structure
  * @put_userptr: inform the allocator that a USERPTR buffer will no longer
  *		 be used
+ * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
+ *		   used for DMABUF memory types; alloc_ctx is the alloc context
+ *		   dbuf is the shared dma_buf; returns NULL on failure;
+ *		   allocator private per-buffer structure on success;
+ *		   this needs to be used for further accesses to the buffer
+ * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
+ *		   buffer is no longer used; the buf_priv argument is the
+ *		   allocator private per-buffer structure previously returned
+ *		   from the attach_dmabuf callback
+ * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
+ *		of dmabuf is informed that this driver is going to use the
+ *		dmabuf
+ * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
+ *		  that this driver is done using the dmabuf for now
  * @vaddr:	return a kernel virtual address to a given memory buffer
  *		associated with the passed private structure or NULL if no
  *		such mapping exists
@@ -56,6 +71,8 @@ struct vb2_fileio_data;
  * Required ops for USERPTR types: get_userptr, put_userptr.
  * Required ops for MMAP types: alloc, put, num_users, mmap.
  * Required ops for read/write access types: alloc, put, num_users, vaddr
+ * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf,
+ *				  unmap_dmabuf.
  */
 struct vb2_mem_ops {
 	void		*(*alloc)(void *alloc_ctx, unsigned long size);
@@ -65,6 +82,12 @@ struct vb2_mem_ops {
 					unsigned long size, int write);
 	void		(*put_userptr)(void *buf_priv);
 
+	void		*(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
+				unsigned long size, int write);
+	void		(*detach_dmabuf)(void *buf_priv);
+	int		(*map_dmabuf)(void *buf_priv);
+	void		(*unmap_dmabuf)(void *buf_priv);
+
 	void		*(*vaddr)(void *buf_priv);
 	void		*(*cookie)(void *buf_priv);
 
@@ -75,6 +98,8 @@ struct vb2_mem_ops {
 
 struct vb2_plane {
 	void			*mem_priv;
+	struct dma_buf		*dbuf;
+	unsigned int		dbuf_mapped;
 };
 
 /**
@@ -83,12 +108,14 @@ struct vb2_plane {
  * @VB2_USERPTR:	driver supports USERPTR with streaming API
  * @VB2_READ:		driver supports read() style access
  * @VB2_WRITE:		driver supports write() style access
+ * @VB2_DMABUF:		driver supports DMABUF with streaming API
  */
 enum vb2_io_modes {
 	VB2_MMAP	= (1 << 0),
 	VB2_USERPTR	= (1 << 1),
 	VB2_READ	= (1 << 2),
 	VB2_WRITE	= (1 << 3),
+	VB2_DMABUF	= (1 << 4),
 };
 
 /**
-- 
1.7.5.4

[PATCHv5 04/13] v4l: vb: remove warnings about MEMORY_DMABUF

[Tomasz Stanislawski]

From: Sumit Semwal <sumit.semwal@ti.com>

Adding DMABUF memory type causes videobuf to complain about not using it
in some switch cases. This patch removes these warnings.

Signed-off-by: Sumit Semwal <sumit.semwal@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/videobuf-core.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index de4fa4e..b457c8b 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -335,6 +335,9 @@ static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 	case V4L2_MEMORY_OVERLAY:
 		b->m.offset  = vb->boff;
 		break;
+	case V4L2_MEMORY_DMABUF:
+		/* DMABUF is not handled in videobuf framework */
+		break;
 	}
 
 	b->flags    = 0;
@@ -411,6 +414,7 @@ int __videobuf_mmap_setup(struct videobuf_queue *q,
 			break;
 		case V4L2_MEMORY_USERPTR:
 		case V4L2_MEMORY_OVERLAY:
+		case V4L2_MEMORY_DMABUF:
 			/* nothing */
 			break;
 		}
-- 
1.7.5.4

[PATCHv5 05/13] v4l: vb2-dma-contig: Shorten vb2_dma_contig prefix to vb2_dc

[Tomasz Stanislawski]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/videobuf2-dma-contig.c |   36 ++++++++++++++--------------
 1 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
index f17ad98..5207eb1 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -31,9 +31,9 @@ struct vb2_dc_buf {
 	struct vb2_vmarea_handler	handler;
 };
 
-static void vb2_dma_contig_put(void *buf_priv);
+static void vb2_dc_put(void *buf_priv);
 
-static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size)
+static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size)
 {
 	struct vb2_dc_conf *conf = alloc_ctx;
 	struct vb2_dc_buf *buf;
@@ -55,7 +55,7 @@ static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size)
 	buf->size = size;
 
 	buf->handler.refcount = &buf->refcount;
-	buf->handler.put = vb2_dma_contig_put;
+	buf->handler.put = vb2_dc_put;
 	buf->handler.arg = buf;
 
 	atomic_inc(&buf->refcount);
@@ -63,7 +63,7 @@ static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size)
 	return buf;
 }
 
-static void vb2_dma_contig_put(void *buf_priv)
+static void vb2_dc_put(void *buf_priv)
 {
 	struct vb2_dc_buf *buf = buf_priv;
 
@@ -74,14 +74,14 @@ static void vb2_dma_contig_put(void *buf_priv)
 	}
 }
 
-static void *vb2_dma_contig_cookie(void *buf_priv)
+static void *vb2_dc_cookie(void *buf_priv)
 {
 	struct vb2_dc_buf *buf = buf_priv;
 
 	return &buf->dma_addr;
 }
 
-static void *vb2_dma_contig_vaddr(void *buf_priv)
+static void *vb2_dc_vaddr(void *buf_priv)
 {
 	struct vb2_dc_buf *buf = buf_priv;
 	if (!buf)
@@ -90,14 +90,14 @@ static void *vb2_dma_contig_vaddr(void *buf_priv)
 	return buf->vaddr;
 }
 
-static unsigned int vb2_dma_contig_num_users(void *buf_priv)
+static unsigned int vb2_dc_num_users(void *buf_priv)
 {
 	struct vb2_dc_buf *buf = buf_priv;
 
 	return atomic_read(&buf->refcount);
 }
 
-static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma)
+static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
 {
 	struct vb2_dc_buf *buf = buf_priv;
 
@@ -110,7 +110,7 @@ static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma)
 				  &vb2_common_vm_ops, &buf->handler);
 }
 
-static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr,
+static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 					unsigned long size, int write)
 {
 	struct vb2_dc_buf *buf;
@@ -137,7 +137,7 @@ static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	return buf;
 }
 
-static void vb2_dma_contig_put_userptr(void *mem_priv)
+static void vb2_dc_put_userptr(void *mem_priv)
 {
 	struct vb2_dc_buf *buf = mem_priv;
 
@@ -149,14 +149,14 @@ static void vb2_dma_contig_put_userptr(void *mem_priv)
 }
 
 const struct vb2_mem_ops vb2_dma_contig_memops = {
-	.alloc		= vb2_dma_contig_alloc,
-	.put		= vb2_dma_contig_put,
-	.cookie		= vb2_dma_contig_cookie,
-	.vaddr		= vb2_dma_contig_vaddr,
-	.mmap		= vb2_dma_contig_mmap,
-	.get_userptr	= vb2_dma_contig_get_userptr,
-	.put_userptr	= vb2_dma_contig_put_userptr,
-	.num_users	= vb2_dma_contig_num_users,
+	.alloc		= vb2_dc_alloc,
+	.put		= vb2_dc_put,
+	.cookie		= vb2_dc_cookie,
+	.vaddr		= vb2_dc_vaddr,
+	.mmap		= vb2_dc_mmap,
+	.get_userptr	= vb2_dc_get_userptr,
+	.put_userptr	= vb2_dc_put_userptr,
+	.num_users	= vb2_dc_num_users,
 };
 EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
 
-- 
1.7.5.4

[PATCHv5 06/13] v4l: vb2-dma-contig: Remove unneeded allocation context structure

[Tomasz Stanislawski]

vb2-dma-contig returns a vb2_dc_conf structure instance as the vb2
allocation context. That structure only stores a pointer to the physical
device. Remove it and use the device pointer directly as the allocation
context.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/videobuf2-dma-contig.c |   29 ++++++---------------------
 1 files changed, 7 insertions(+), 22 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
index 5207eb1..ff0a662 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -17,12 +17,8 @@
 #include <media/videobuf2-core.h>
 #include <media/videobuf2-memops.h>
 
-struct vb2_dc_conf {
-	struct device		*dev;
-};
-
 struct vb2_dc_buf {
-	struct vb2_dc_conf		*conf;
+	struct device			*dev;
 	void				*vaddr;
 	dma_addr_t			dma_addr;
 	unsigned long			size;
@@ -35,23 +31,21 @@ static void vb2_dc_put(void *buf_priv);
 
 static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size)
 {
-	struct vb2_dc_conf *conf = alloc_ctx;
+	struct device *dev = alloc_ctx;
 	struct vb2_dc_buf *buf;
 
 	buf = kzalloc(sizeof *buf, GFP_KERNEL);
 	if (!buf)
 		return ERR_PTR(-ENOMEM);
 
-	buf->vaddr = dma_alloc_coherent(conf->dev, size, &buf->dma_addr,
-					GFP_KERNEL);
+	buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr, GFP_KERNEL);
 	if (!buf->vaddr) {
-		dev_err(conf->dev, "dma_alloc_coherent of size %ld failed\n",
-			size);
+		dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size);
 		kfree(buf);
 		return ERR_PTR(-ENOMEM);
 	}
 
-	buf->conf = conf;
+	buf->dev = dev;
 	buf->size = size;
 
 	buf->handler.refcount = &buf->refcount;
@@ -68,7 +62,7 @@ static void vb2_dc_put(void *buf_priv)
 	struct vb2_dc_buf *buf = buf_priv;
 
 	if (atomic_dec_and_test(&buf->refcount)) {
-		dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr,
+		dma_free_coherent(buf->dev, buf->size, buf->vaddr,
 				  buf->dma_addr);
 		kfree(buf);
 	}
@@ -162,21 +156,12 @@ EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
 
 void *vb2_dma_contig_init_ctx(struct device *dev)
 {
-	struct vb2_dc_conf *conf;
-
-	conf = kzalloc(sizeof *conf, GFP_KERNEL);
-	if (!conf)
-		return ERR_PTR(-ENOMEM);
-
-	conf->dev = dev;
-
-	return conf;
+	return dev;
 }
 EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx);
 
 void vb2_dma_contig_cleanup_ctx(void *alloc_ctx)
 {
-	kfree(alloc_ctx);
 }
 EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx);
 
-- 
1.7.5.4

[PATCHv5 07/13] v4l: vb2-dma-contig: Reorder functions

[Tomasz Stanislawski]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Group functions by buffer type.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/videobuf2-dma-contig.c |   92 ++++++++++++++++-----------
 1 files changed, 54 insertions(+), 38 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
index ff0a662..476e536 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -20,14 +20,56 @@
 struct vb2_dc_buf {
 	struct device			*dev;
 	void				*vaddr;
-	dma_addr_t			dma_addr;
 	unsigned long			size;
-	struct vm_area_struct		*vma;
-	atomic_t			refcount;
+	dma_addr_t			dma_addr;
+
+	/* MMAP related */
 	struct vb2_vmarea_handler	handler;
+	atomic_t			refcount;
+
+	/* USERPTR related */
+	struct vm_area_struct		*vma;
 };
 
-static void vb2_dc_put(void *buf_priv);
+/*********************************************/
+/*         callbacks for all buffers         */
+/*********************************************/
+
+static void *vb2_dc_cookie(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+
+	return &buf->dma_addr;
+}
+
+static void *vb2_dc_vaddr(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+
+	return buf->vaddr;
+}
+
+static unsigned int vb2_dc_num_users(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+
+	return atomic_read(&buf->refcount);
+}
+
+/*********************************************/
+/*        callbacks for MMAP buffers         */
+/*********************************************/
+
+static void vb2_dc_put(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+
+	if (!atomic_dec_and_test(&buf->refcount))
+		return;
+
+	dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr);
+	kfree(buf);
+}
 
 static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size)
 {
@@ -57,40 +99,6 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size)
 	return buf;
 }
 
-static void vb2_dc_put(void *buf_priv)
-{
-	struct vb2_dc_buf *buf = buf_priv;
-
-	if (atomic_dec_and_test(&buf->refcount)) {
-		dma_free_coherent(buf->dev, buf->size, buf->vaddr,
-				  buf->dma_addr);
-		kfree(buf);
-	}
-}
-
-static void *vb2_dc_cookie(void *buf_priv)
-{
-	struct vb2_dc_buf *buf = buf_priv;
-
-	return &buf->dma_addr;
-}
-
-static void *vb2_dc_vaddr(void *buf_priv)
-{
-	struct vb2_dc_buf *buf = buf_priv;
-	if (!buf)
-		return 0;
-
-	return buf->vaddr;
-}
-
-static unsigned int vb2_dc_num_users(void *buf_priv)
-{
-	struct vb2_dc_buf *buf = buf_priv;
-
-	return atomic_read(&buf->refcount);
-}
-
 static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
 {
 	struct vb2_dc_buf *buf = buf_priv;
@@ -104,6 +112,10 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
 				  &vb2_common_vm_ops, &buf->handler);
 }
 
+/*********************************************/
+/*       callbacks for USERPTR buffers       */
+/*********************************************/
+
 static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 					unsigned long size, int write)
 {
@@ -142,6 +154,10 @@ static void vb2_dc_put_userptr(void *mem_priv)
 	kfree(buf);
 }
 
+/*********************************************/
+/*       DMA CONTIG exported functions       */
+/*********************************************/
+
 const struct vb2_mem_ops vb2_dma_contig_memops = {
 	.alloc		= vb2_dc_alloc,
 	.put		= vb2_dc_put,
-- 
1.7.5.4

[PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Tomasz Stanislawski]

From: Andrzej Pietrasiewicz <andrzej.p@samsung.com>

This patch introduces usage of dma_map_sg to map memory behind
a userspace pointer to a device as dma-contiguous mapping.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
	[bugfixing]
Signed-off-by: Kamil Debski <k.debski@samsung.com>
	[bugfixing]
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
	[add sglist subroutines/code refactoring]
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/media/video/videobuf2-dma-contig.c |  279 ++++++++++++++++++++++++++--
 1 files changed, 262 insertions(+), 17 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
index 476e536..9cbc8d4 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -11,6 +11,8 @@
  */
 
 #include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
 
@@ -22,6 +24,8 @@ struct vb2_dc_buf {
 	void				*vaddr;
 	unsigned long			size;
 	dma_addr_t			dma_addr;
+	enum dma_data_direction		dma_dir;
+	struct sg_table			*dma_sgt;
 
 	/* MMAP related */
 	struct vb2_vmarea_handler	handler;
@@ -32,6 +36,95 @@ struct vb2_dc_buf {
 };
 
 /*********************************************/
+/*        scatterlist table functions        */
+/*********************************************/
+
+static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages,
+	unsigned int n_pages, unsigned long offset, unsigned long size)
+{
+	struct sg_table *sgt;
+	unsigned int chunks;
+	unsigned int i;
+	unsigned int cur_page;
+	int ret;
+	struct scatterlist *s;
+
+	sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
+	if (!sgt)
+		return ERR_PTR(-ENOMEM);
+
+	/* compute number of chunks */
+	chunks = 1;
+	for (i = 1; i < n_pages; ++i)
+		if (pages[i] != pages[i - 1] + 1)
+			++chunks;
+
+	ret = sg_alloc_table(sgt, chunks, GFP_KERNEL);
+	if (ret) {
+		kfree(sgt);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* merging chunks and putting them into the scatterlist */
+	cur_page = 0;
+	for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
+		unsigned long chunk_size;
+		unsigned int j;
+
+		for (j = cur_page + 1; j < n_pages; ++j)
+			if (pages[j] != pages[j - 1] + 1)
+				break;
+
+		chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset;
+		sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
+		size -= chunk_size;
+		offset = 0;
+		cur_page = j;
+	}
+
+	return sgt;
+}
+
+static void vb2_dc_release_sgtable(struct sg_table *sgt)
+{
+	sg_free_table(sgt);
+	kfree(sgt);
+}
+
+static void vb2_dc_sgt_foreach_page(struct sg_table *sgt,
+	void (*cb)(struct page *pg))
+{
+	struct scatterlist *s;
+	unsigned int i;
+
+	for_each_sg(sgt->sgl, s, sgt->nents, i) {
+		struct page *page = sg_page(s);
+		unsigned int n_pages = PAGE_ALIGN(s->offset + s->length)
+			>> PAGE_SHIFT;
+		unsigned int j;
+
+		for (j = 0; j < n_pages; ++j, ++page)
+			cb(page);
+	}
+}
+
+static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
+{
+	struct scatterlist *s;
+	dma_addr_t expected = sg_dma_address(sgt->sgl);
+	unsigned int i;
+	unsigned long size = 0;
+
+	for_each_sg(sgt->sgl, s, sgt->nents, i) {
+		if (sg_dma_address(s) != expected)
+			break;
+		expected = sg_dma_address(s) + sg_dma_len(s);
+		size += sg_dma_len(s);
+	}
+	return size;
+}
+
+/*********************************************/
 /*         callbacks for all buffers         */
 /*********************************************/
 
@@ -116,42 +209,194 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
 /*       callbacks for USERPTR buffers       */
 /*********************************************/
 
+static inline int vma_is_io(struct vm_area_struct *vma)
+{
+	return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
+}
+
+static struct vm_area_struct *vb2_dc_get_user_vma(
+	unsigned long start, unsigned long size)
+{
+	struct vm_area_struct *vma;
+
+	/* current->mm->mmap_sem is taken by videobuf2 core */
+	vma = find_vma(current->mm, start);
+	if (!vma) {
+		printk(KERN_ERR "no vma for address %lu\n", start);
+		return ERR_PTR(-EFAULT);
+	}
+
+	if (vma->vm_end - vma->vm_start < size) {
+		printk(KERN_ERR "vma at %lu is too small for %lu bytes\n",
+			start, size);
+		return ERR_PTR(-EFAULT);
+	}
+
+	vma = vb2_get_vma(vma);
+	if (!vma) {
+		printk(KERN_ERR "failed to copy vma\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return vma;
+}
+
+static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
+	int n_pages, struct vm_area_struct *vma, int write)
+{
+	if (vma_is_io(vma)) {
+		unsigned int i;
+
+		for (i = 0; i < n_pages; ++i, start += PAGE_SIZE) {
+			unsigned long pfn;
+			int ret = follow_pfn(vma, start, &pfn);
+
+			if (ret) {
+				printk(KERN_ERR "no page for address %lu\n",
+					start);
+				return ret;
+			}
+			pages[i] = pfn_to_page(pfn);
+		}
+	} else {
+		unsigned int n;
+
+		n = get_user_pages(current, current->mm, start & PAGE_MASK,
+			n_pages, write, 1, pages, NULL);
+		if (n != n_pages) {
+			printk(KERN_ERR "got only %d of %d user pages\n",
+				n, n_pages);
+			while (n)
+				put_page(pages[--n]);
+			return -EFAULT;
+		}
+	}
+
+	return 0;
+}
+
+static void vb2_dc_put_dirty_page(struct page *page)
+{
+	set_page_dirty_lock(page);
+	put_page(page);
+}
+
+static void vb2_dc_put_userptr(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
+	if (!vma_is_io(buf->vma))
+		vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);
+
+	vb2_dc_release_sgtable(sgt);
+	vb2_put_vma(buf->vma);
+	kfree(buf);
+}
+
 static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
-					unsigned long size, int write)
+	unsigned long size, int write)
 {
 	struct vb2_dc_buf *buf;
-	struct vm_area_struct *vma;
-	dma_addr_t dma_addr = 0;
-	int ret;
+	unsigned long start;
+	unsigned long end;
+	unsigned long offset;
+	struct page **pages;
+	int n_pages;
+	int ret = 0;
+	struct sg_table *sgt;
+	unsigned long contig_size;
 
 	buf = kzalloc(sizeof *buf, GFP_KERNEL);
 	if (!buf)
 		return ERR_PTR(-ENOMEM);
 
-	ret = vb2_get_contig_userptr(vaddr, size, &vma, &dma_addr);
+	buf->dev = alloc_ctx;
+	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	start = vaddr & PAGE_MASK;
+	offset = vaddr & ~PAGE_MASK;
+	end = PAGE_ALIGN(vaddr + size);
+	n_pages = (end - start) >> PAGE_SHIFT;
+
+	pages = kmalloc(n_pages * sizeof pages[0], GFP_KERNEL);
+	if (!pages) {
+		ret = -ENOMEM;
+		printk(KERN_ERR "failed to allocate pages table\n");
+		goto fail_buf;
+	}
+
+	buf->vma = vb2_dc_get_user_vma(start, size);
+	if (IS_ERR(buf->vma)) {
+		printk(KERN_ERR "failed to get VMA\n");
+		ret = PTR_ERR(buf->vma);
+		goto fail_pages;
+	}
+
+	/* extract page list from userspace mapping */
+	ret = vb2_dc_get_user_pages(start, pages, n_pages, buf->vma, write);
 	if (ret) {
-		printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n",
-				vaddr);
-		kfree(buf);
-		return ERR_PTR(ret);
+		printk(KERN_ERR "failed to get user pages\n");
+		goto fail_vma;
+	}
+
+	sgt = vb2_dc_pages_to_sgt(pages, n_pages, offset, size);
+	if (IS_ERR(sgt)) {
+		printk(KERN_ERR "failed to create scatterlist table\n");
+		ret = -ENOMEM;
+		goto fail_get_user_pages;
+	}
+
+	/* pages are no longer needed */
+	kfree(pages);
+	pages = NULL;
+
+	sgt->nents = dma_map_sg(buf->dev, sgt->sgl, sgt->orig_nents,
+		buf->dma_dir);
+	if (sgt->nents <= 0) {
+		printk(KERN_ERR "failed to map scatterlist\n");
+		ret = -EIO;
+		goto fail_sgt;
 	}
 
+	contig_size = vb2_dc_get_contiguous_size(sgt);
+	if (contig_size < size) {
+		printk(KERN_ERR "contiguous mapping is too small %lu/%lu\n",
+			contig_size, size);
+		ret = -EFAULT;
+		goto fail_map_sg;
+	}
+
+	buf->dma_addr = sg_dma_address(sgt->sgl);
 	buf->size = size;
-	buf->dma_addr = dma_addr;
-	buf->vma = vma;
+	buf->dma_sgt = sgt;
 
 	return buf;
-}
 
-static void vb2_dc_put_userptr(void *mem_priv)
-{
-	struct vb2_dc_buf *buf = mem_priv;
+fail_map_sg:
+	dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
 
-	if (!buf)
-		return;
+fail_sgt:
+	if (!vma_is_io(buf->vma))
+		vb2_dc_sgt_foreach_page(sgt, put_page);
+	vb2_dc_release_sgtable(sgt);
+
+fail_get_user_pages:
+	if (pages && !vma_is_io(buf->vma))
+		while (n_pages)
+			put_page(pages[--n_pages]);
 
+fail_vma:
 	vb2_put_vma(buf->vma);
+
+fail_pages:
+	kfree(pages); /* kfree is NULL-proof */
+
+fail_buf:
 	kfree(buf);
+
+	return ERR_PTR(ret);
 }
 
 /*********************************************/
-- 
1.7.5.4

[PATCHv5 09/13] v4l: vb2: add prepare/finish callbacks to allocators

[Tomasz Stanislawski]

From: Marek Szyprowski <m.szyprowski@samsung.com>

This patch adds support for prepare/finish callbacks in VB2 allocators. These
callback are used for buffer flushing.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/videobuf2-core.c |   11 +++++++++++
 include/media/videobuf2-core.h       |    7 +++++++
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index d26b1cc..b431dc6 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -842,6 +842,7 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 {
 	struct vb2_queue *q = vb->vb2_queue;
 	unsigned long flags;
+	unsigned int plane;
 
 	if (vb->state != VB2_BUF_STATE_ACTIVE)
 		return;
@@ -852,6 +853,10 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 	dprintk(4, "Done processing on buffer %d, state: %d\n",
 			vb->v4l2_buf.index, vb->state);
 
+	/* sync buffers */
+	for (plane = 0; plane < vb->num_planes; ++plane)
+		call_memop(q, finish, vb->planes[plane].mem_priv);
+
 	/* Add the buffer to the done buffers list */
 	spin_lock_irqsave(&q->done_lock, flags);
 	vb->state = state;
@@ -1134,9 +1139,15 @@ err:
 static void __enqueue_in_driver(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
+	unsigned int plane;
 
 	vb->state = VB2_BUF_STATE_ACTIVE;
 	atomic_inc(&q->queued_count);
+
+	/* sync buffers */
+	for (plane = 0; plane < vb->num_planes; ++plane)
+		call_memop(q, prepare, vb->planes[plane].mem_priv);
+
 	q->ops->buf_queue(vb);
 }
 
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 859bbaf..d079f92 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -56,6 +56,10 @@ struct vb2_fileio_data;
  *		dmabuf
  * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
  *		  that this driver is done using the dmabuf for now
+ * @prepare:	called everytime the buffer is passed from userspace to the
+ *		driver, usefull for cache synchronisation, optional
+ * @finish:	called everytime the buffer is passed back from the driver
+ *		to the userspace, also optional
  * @vaddr:	return a kernel virtual address to a given memory buffer
  *		associated with the passed private structure or NULL if no
  *		such mapping exists
@@ -82,6 +86,9 @@ struct vb2_mem_ops {
 					unsigned long size, int write);
 	void		(*put_userptr)(void *buf_priv);
 
+	void		(*prepare)(void *buf_priv);
+	void		(*finish)(void *buf_priv);
+
 	void		*(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
 				unsigned long size, int write);
 	void		(*detach_dmabuf)(void *buf_priv);
-- 
1.7.5.4

[PATCHv5 10/13] v4l: vb2-dma-contig: add prepare/finish to dma-contig allocator

[Tomasz Stanislawski]

From: Marek Szyprowski <m.szyprowski@samsung.com>

Add prepare/finish callbacks to vb2-dma-contig allocator.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/media/video/videobuf2-dma-contig.c |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
index 9cbc8d4..93f86a0 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -149,6 +149,28 @@ static unsigned int vb2_dc_num_users(void *buf_priv)
 	return atomic_read(&buf->refcount);
 }
 
+static void vb2_dc_prepare(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (!sgt)
+		return;
+
+	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
+static void vb2_dc_finish(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (!sgt)
+		return;
+
+	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
 /*********************************************/
 /*        callbacks for MMAP buffers         */
 /*********************************************/
@@ -411,6 +433,8 @@ const struct vb2_mem_ops vb2_dma_contig_memops = {
 	.mmap		= vb2_dc_mmap,
 	.get_userptr	= vb2_dc_get_userptr,
 	.put_userptr	= vb2_dc_put_userptr,
+	.prepare	= vb2_dc_prepare,
+	.finish		= vb2_dc_finish,
 	.num_users	= vb2_dc_num_users,
 };
 EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
-- 
1.7.5.4

[PATCHv5 11/13] v4l: vb2-dma-contig: add support for dma_buf importing

[Tomasz Stanislawski]

From: Sumit Semwal <sumit.semwal@ti.com>

This patch makes changes for adding dma-contig as a dma_buf user. It provides
function implementations for the {attach, detach, map, unmap}_dmabuf()
mem_ops of DMABUF memory type.

Signed-off-by: Sumit Semwal <sumit.semwal@ti.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
	[author of the original patch]
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
	[integration with refactored dma-contig allocator]
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/videobuf2-dma-contig.c |  113 ++++++++++++++++++++++++++++
 1 files changed, 113 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
index 93f86a0..5cf3107 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -10,6 +10,7 @@
  * the Free Software Foundation.
  */
 
+#include <linux/dma-buf.h>
 #include <linux/module.h>
 #include <linux/scatterlist.h>
 #include <linux/sched.h>
@@ -33,6 +34,9 @@ struct vb2_dc_buf {
 
 	/* USERPTR related */
 	struct vm_area_struct		*vma;
+
+	/* DMABUF related */
+	struct dma_buf_attachment	*db_attach;
 };
 
 /*********************************************/
@@ -422,6 +426,111 @@ fail_buf:
 }
 
 /*********************************************/
+/*       callbacks for DMABUF buffers        */
+/*********************************************/
+
+static int vb2_dc_map_dmabuf(void *mem_priv)
+{
+	struct vb2_dc_buf *buf = mem_priv;
+	struct sg_table *sgt;
+	unsigned long contig_size;
+
+	if (WARN_ON(!buf->db_attach)) {
+		printk(KERN_ERR "trying to pin a non attached buffer\n");
+		return -EINVAL;
+	}
+
+	if (WARN_ON(buf->dma_sgt)) {
+		printk(KERN_ERR "dmabuf buffer is already pinned\n");
+		return 0;
+	}
+
+	/* get the associated scatterlist for this buffer */
+	sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
+	if (IS_ERR_OR_NULL(sgt)) {
+		printk(KERN_ERR "Error getting dmabuf scatterlist\n");
+		return -EINVAL;
+	}
+
+	/* checking if dmabuf is big enough to store contiguous chunk */
+	contig_size = vb2_dc_get_contiguous_size(sgt);
+	if (contig_size < buf->size) {
+		printk(KERN_ERR "contiguous chunk is too small %lu/%lu b\n",
+			contig_size, buf->size);
+		dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
+		return -EFAULT;
+	}
+
+	buf->dma_addr = sg_dma_address(sgt->sgl);
+	buf->dma_sgt = sgt;
+
+	return 0;
+}
+
+static void vb2_dc_unmap_dmabuf(void *mem_priv)
+{
+	struct vb2_dc_buf *buf = mem_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (WARN_ON(!buf->db_attach)) {
+		printk(KERN_ERR "trying to unpin a not attached buffer\n");
+		return;
+	}
+
+	if (WARN_ON(!sgt)) {
+		printk(KERN_ERR "dmabuf buffer is already unpinned\n");
+		return;
+	}
+
+	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
+
+	buf->dma_addr = 0;
+	buf->dma_sgt = NULL;
+}
+
+static void vb2_dc_detach_dmabuf(void *mem_priv)
+{
+	struct vb2_dc_buf *buf = mem_priv;
+
+	/* if vb2 works correctly you should never detach mapped buffer */
+	if (WARN_ON(buf->dma_addr))
+		vb2_dc_unmap_dmabuf(buf);
+
+	/* detach this attachment */
+	dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach);
+	kfree(buf);
+}
+
+static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
+	unsigned long size, int write)
+{
+	struct vb2_dc_buf *buf;
+	struct dma_buf_attachment *dba;
+
+	if (dbuf->size < size)
+		return ERR_PTR(-EFAULT);
+
+	buf = kzalloc(sizeof *buf, GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	buf->dev = alloc_ctx;
+	/* create attachment for the dmabuf with the user device */
+	dba = dma_buf_attach(dbuf, buf->dev);
+	if (IS_ERR(dba)) {
+		printk(KERN_ERR "failed to attach dmabuf\n");
+		kfree(buf);
+		return dba;
+	}
+
+	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->size = size;
+	buf->db_attach = dba;
+
+	return buf;
+}
+
+/*********************************************/
 /*       DMA CONTIG exported functions       */
 /*********************************************/
 
@@ -435,6 +544,10 @@ const struct vb2_mem_ops vb2_dma_contig_memops = {
 	.put_userptr	= vb2_dc_put_userptr,
 	.prepare	= vb2_dc_prepare,
 	.finish		= vb2_dc_finish,
+	.map_dmabuf	= vb2_dc_map_dmabuf,
+	.unmap_dmabuf	= vb2_dc_unmap_dmabuf,
+	.attach_dmabuf	= vb2_dc_attach_dmabuf,
+	.detach_dmabuf	= vb2_dc_detach_dmabuf,
 	.num_users	= vb2_dc_num_users,
 };
 EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
-- 
1.7.5.4

[PATCHv5 12/13] v4l: s5p-tv: mixer: support for dmabuf importing

[Tomasz Stanislawski]

This patch enhances s5p-tv with support for DMABUF importing via
V4L2_MEMORY_DMABUF memory type.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/media/video/s5p-tv/Kconfig       |    1 +
 drivers/media/video/s5p-tv/mixer_video.c |    2 +-
 2 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/s5p-tv/Kconfig b/drivers/media/video/s5p-tv/Kconfig
index f248b28..2e80126 100644
--- a/drivers/media/video/s5p-tv/Kconfig
+++ b/drivers/media/video/s5p-tv/Kconfig
@@ -10,6 +10,7 @@ config VIDEO_SAMSUNG_S5P_TV
 	bool "Samsung TV driver for S5P platform (experimental)"
 	depends on PLAT_S5P && PM_RUNTIME
 	depends on EXPERIMENTAL
+	select DMA_SHARED_BUFFER
 	default n
 	---help---
 	  Say Y here to enable selecting the TV output devices for
diff --git a/drivers/media/video/s5p-tv/mixer_video.c b/drivers/media/video/s5p-tv/mixer_video.c
index f7ca5cc..6b45d93 100644
--- a/drivers/media/video/s5p-tv/mixer_video.c
+++ b/drivers/media/video/s5p-tv/mixer_video.c
@@ -1074,7 +1074,7 @@ struct mxr_layer *mxr_base_layer_create(struct mxr_device *mdev,
 
 	layer->vb_queue = (struct vb2_queue) {
 		.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE,
-		.io_modes = VB2_MMAP | VB2_USERPTR,
+		.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF,
 		.drv_priv = layer,
 		.buf_struct_size = sizeof(struct mxr_buffer),
 		.ops = &mxr_video_qops,
-- 
1.7.5.4

[PATCHv5 13/13] v4l: s5p-fimc: support for dmabuf importing

[Tomasz Stanislawski]

This patch enhances s5p-fimc with support for DMABUF importing via
V4L2_MEMORY_DMABUF memory type.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
 drivers/media/video/Kconfig                 |    1 +
 drivers/media/video/s5p-fimc/fimc-capture.c |    2 +-
 2 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index f2479c5..9de9ddc 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -1133,6 +1133,7 @@ config  VIDEO_SAMSUNG_S5P_FIMC
 		VIDEO_V4L2_SUBDEV_API && EXPERIMENTAL
 	select VIDEOBUF2_DMA_CONTIG
 	select V4L2_MEM2MEM_DEV
+	select DMA_SHARED_BUFFER
 	---help---
 	  This is a v4l2 driver for Samsung S5P and EXYNOS4 camera
 	  host interface and video postprocessor.
diff --git a/drivers/media/video/s5p-fimc/fimc-capture.c b/drivers/media/video/s5p-fimc/fimc-capture.c
index b06efd2..38fb39e 100644
--- a/drivers/media/video/s5p-fimc/fimc-capture.c
+++ b/drivers/media/video/s5p-fimc/fimc-capture.c
@@ -1530,7 +1530,7 @@ int fimc_register_capture_device(struct fimc_dev *fimc,
 	q = &fimc->vid_cap.vbq;
 	memset(q, 0, sizeof(*q));
 	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
-	q->io_modes = VB2_MMAP | VB2_USERPTR;
+	q->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
 	q->drv_priv = fimc->vid_cap.ctx;
 	q->ops = &fimc_capture_qops;
 	q->mem_ops = &vb2_dma_contig_memops;
-- 
1.7.5.4

Re: [PATCHv5 00/13] Integration of videobuf2 with dmabuf

[Rob Landley]

On 04/20/2012 09:45 AM, Tomasz Stanislawski wrote:
> Hello everyone,
> This patchset adds support for DMABUF [2] importing to V4L2 stack.
> The support for DMABUF exporting was moved to separate patchset
> due to dependency on patches for DMA mapping redesign by
> Marek Szyprowski [4].

Would it be an an option to _not_ cc: all 14 patches to the linux-doc
list when 12 of them have nothing to do with documentation? (Or do the
tools not allow for that?)

Just wondering...

Rob
-- 
GNU/Linux isn't: Linux=GPLv2, GNU=GPLv3+, they can't share code.
Either it's "mere aggregation", or a license violation.  Pick one.

Re: [PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Laurent Pinchart]

Hi Tomasz,

Thanks for the patch.

On Friday 20 April 2012 16:45:29 Tomasz Stanislawski wrote:
> From: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
> 
> This patch introduces usage of dma_map_sg to map memory behind
> a userspace pointer to a device as dma-contiguous mapping.
> 
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> 	[bugfixing]
> Signed-off-by: Kamil Debski <k.debski@samsung.com>
> 	[bugfixing]
> Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
> 	[add sglist subroutines/code refactoring]
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

-- 
Regards,

Laurent Pinchart

Re: [PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Subash Patel]

Hello Thomasz, Laurent,

I found an issue in the function vb2_dc_pages_to_sgt() below. I saw that 
during the attach, the size of the SGT and size requested mis-matched 
(by atleast 8k bytes). Hence I made a small correction to the code as 
below. I could then attach the importer properly.

Regards,
Subash

On 04/20/2012 08:15 PM, Tomasz Stanislawski wrote:
> From: Andrzej Pietrasiewicz<andrzej.p@samsung.com>
>
> This patch introduces usage of dma_map_sg to map memory behind
> a userspace pointer to a device as dma-contiguous mapping.
>
> Signed-off-by: Andrzej Pietrasiewicz<andrzej.p@samsung.com>
> Signed-off-by: Marek Szyprowski<m.szyprowski@samsung.com>
> 	[bugfixing]
> Signed-off-by: Kamil Debski<k.debski@samsung.com>
> 	[bugfixing]
> Signed-off-by: Tomasz Stanislawski<t.stanislaws@samsung.com>
> 	[add sglist subroutines/code refactoring]
> Signed-off-by: Kyungmin Park<kyungmin.park@samsung.com>
> ---
>   drivers/media/video/videobuf2-dma-contig.c |  279 ++++++++++++++++++++++++++--
>   1 files changed, 262 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
> index 476e536..9cbc8d4 100644
> --- a/drivers/media/video/videobuf2-dma-contig.c
> +++ b/drivers/media/video/videobuf2-dma-contig.c
> @@ -11,6 +11,8 @@
>    */
>
>   #include<linux/module.h>
> +#include<linux/scatterlist.h>
> +#include<linux/sched.h>
>   #include<linux/slab.h>
>   #include<linux/dma-mapping.h>
>
> @@ -22,6 +24,8 @@ struct vb2_dc_buf {
>   	void				*vaddr;
>   	unsigned long			size;
>   	dma_addr_t			dma_addr;
> +	enum dma_data_direction		dma_dir;
> +	struct sg_table			*dma_sgt;
>
>   	/* MMAP related */
>   	struct vb2_vmarea_handler	handler;
> @@ -32,6 +36,95 @@ struct vb2_dc_buf {
>   };
>
>   /*********************************************/
> +/*        scatterlist table functions        */
> +/*********************************************/
> +
> +static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages,
> +	unsigned int n_pages, unsigned long offset, unsigned long size)
> +{
> +	struct sg_table *sgt;
> +	unsigned int chunks;
> +	unsigned int i;
> +	unsigned int cur_page;
> +	int ret;
> +	struct scatterlist *s;
> +
> +	sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
> +	if (!sgt)
> +		return ERR_PTR(-ENOMEM);
> +
> +	/* compute number of chunks */
> +	chunks = 1;
> +	for (i = 1; i<  n_pages; ++i)
> +		if (pages[i] != pages[i - 1] + 1)
> +			++chunks;
> +
> +	ret = sg_alloc_table(sgt, chunks, GFP_KERNEL);
> +	if (ret) {
> +		kfree(sgt);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	/* merging chunks and putting them into the scatterlist */
> +	cur_page = 0;
> +	for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
> +		unsigned long chunk_size;
> +		unsigned int j;
		size = PAGE_SIZE;

> +
> +		for (j = cur_page + 1; j<  n_pages; ++j)
		for (j = cur_page + 1; j < n_pages; ++j) {
> +			if (pages[j] != pages[j - 1] + 1)
> +				break;
			size += PAGE
		}
> +
> +		chunk_size = ((j - cur_page)<<  PAGE_SHIFT) - offset;
> +		sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
		[DELETE] size -= chunk_size;
> +		offset = 0;
> +		cur_page = j;
> +	}
> +
> +	return sgt;
> +}
> +
> +static void vb2_dc_release_sgtable(struct sg_table *sgt)
> +{
> +	sg_free_table(sgt);
> +	kfree(sgt);
> +}
> +
> +static void vb2_dc_sgt_foreach_page(struct sg_table *sgt,
> +	void (*cb)(struct page *pg))
> +{
> +	struct scatterlist *s;
> +	unsigned int i;
> +
> +	for_each_sg(sgt->sgl, s, sgt->nents, i) {
> +		struct page *page = sg_page(s);
> +		unsigned int n_pages = PAGE_ALIGN(s->offset + s->length)
> +			>>  PAGE_SHIFT;
> +		unsigned int j;
> +
> +		for (j = 0; j<  n_pages; ++j, ++page)
> +			cb(page);
> +	}
> +}
> +
> +static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
> +{
> +	struct scatterlist *s;
> +	dma_addr_t expected = sg_dma_address(sgt->sgl);
> +	unsigned int i;
> +	unsigned long size = 0;
> +
> +	for_each_sg(sgt->sgl, s, sgt->nents, i) {
> +		if (sg_dma_address(s) != expected)
> +			break;
> +		expected = sg_dma_address(s) + sg_dma_len(s);
> +		size += sg_dma_len(s);
> +	}
> +	return size;
> +}
> +
> +/*********************************************/
>   /*         callbacks for all buffers         */
>   /*********************************************/
>
> @@ -116,42 +209,194 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
>   /*       callbacks for USERPTR buffers       */
>   /*********************************************/
>
> +static inline int vma_is_io(struct vm_area_struct *vma)
> +{
> +	return !!(vma->vm_flags&  (VM_IO | VM_PFNMAP));
> +}
> +
> +static struct vm_area_struct *vb2_dc_get_user_vma(
> +	unsigned long start, unsigned long size)
> +{
> +	struct vm_area_struct *vma;
> +
> +	/* current->mm->mmap_sem is taken by videobuf2 core */
> +	vma = find_vma(current->mm, start);
> +	if (!vma) {
> +		printk(KERN_ERR "no vma for address %lu\n", start);
> +		return ERR_PTR(-EFAULT);
> +	}
> +
> +	if (vma->vm_end - vma->vm_start<  size) {
> +		printk(KERN_ERR "vma at %lu is too small for %lu bytes\n",
> +			start, size);
> +		return ERR_PTR(-EFAULT);
> +	}
> +
> +	vma = vb2_get_vma(vma);
> +	if (!vma) {
> +		printk(KERN_ERR "failed to copy vma\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	return vma;
> +}
> +
> +static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
> +	int n_pages, struct vm_area_struct *vma, int write)
> +{
> +	if (vma_is_io(vma)) {
> +		unsigned int i;
> +
> +		for (i = 0; i<  n_pages; ++i, start += PAGE_SIZE) {
> +			unsigned long pfn;
> +			int ret = follow_pfn(vma, start,&pfn);
> +
> +			if (ret) {
> +				printk(KERN_ERR "no page for address %lu\n",
> +					start);
> +				return ret;
> +			}
> +			pages[i] = pfn_to_page(pfn);
> +		}
> +	} else {
> +		unsigned int n;
> +
> +		n = get_user_pages(current, current->mm, start&  PAGE_MASK,
> +			n_pages, write, 1, pages, NULL);
> +		if (n != n_pages) {
> +			printk(KERN_ERR "got only %d of %d user pages\n",
> +				n, n_pages);
> +			while (n)
> +				put_page(pages[--n]);
> +			return -EFAULT;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static void vb2_dc_put_dirty_page(struct page *page)
> +{
> +	set_page_dirty_lock(page);
> +	put_page(page);
> +}
> +
> +static void vb2_dc_put_userptr(void *buf_priv)
> +{
> +	struct vb2_dc_buf *buf = buf_priv;
> +	struct sg_table *sgt = buf->dma_sgt;
> +
> +	dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
> +	if (!vma_is_io(buf->vma))
> +		vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);
> +
> +	vb2_dc_release_sgtable(sgt);
> +	vb2_put_vma(buf->vma);
> +	kfree(buf);
> +}
> +
>   static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
> -					unsigned long size, int write)
> +	unsigned long size, int write)
>   {
>   	struct vb2_dc_buf *buf;
> -	struct vm_area_struct *vma;
> -	dma_addr_t dma_addr = 0;
> -	int ret;
> +	unsigned long start;
> +	unsigned long end;
> +	unsigned long offset;
> +	struct page **pages;
> +	int n_pages;
> +	int ret = 0;
> +	struct sg_table *sgt;
> +	unsigned long contig_size;
>
>   	buf = kzalloc(sizeof *buf, GFP_KERNEL);
>   	if (!buf)
>   		return ERR_PTR(-ENOMEM);
>
> -	ret = vb2_get_contig_userptr(vaddr, size,&vma,&dma_addr);
> +	buf->dev = alloc_ctx;
> +	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
> +
> +	start = vaddr&  PAGE_MASK;
> +	offset = vaddr&  ~PAGE_MASK;
> +	end = PAGE_ALIGN(vaddr + size);
> +	n_pages = (end - start)>>  PAGE_SHIFT;
> +
> +	pages = kmalloc(n_pages * sizeof pages[0], GFP_KERNEL);
> +	if (!pages) {
> +		ret = -ENOMEM;
> +		printk(KERN_ERR "failed to allocate pages table\n");
> +		goto fail_buf;
> +	}
> +
> +	buf->vma = vb2_dc_get_user_vma(start, size);
> +	if (IS_ERR(buf->vma)) {
> +		printk(KERN_ERR "failed to get VMA\n");
> +		ret = PTR_ERR(buf->vma);
> +		goto fail_pages;
> +	}
> +
> +	/* extract page list from userspace mapping */
> +	ret = vb2_dc_get_user_pages(start, pages, n_pages, buf->vma, write);
>   	if (ret) {
> -		printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n",
> -				vaddr);
> -		kfree(buf);
> -		return ERR_PTR(ret);
> +		printk(KERN_ERR "failed to get user pages\n");
> +		goto fail_vma;
> +	}
> +
> +	sgt = vb2_dc_pages_to_sgt(pages, n_pages, offset, size);
> +	if (IS_ERR(sgt)) {
> +		printk(KERN_ERR "failed to create scatterlist table\n");
> +		ret = -ENOMEM;
> +		goto fail_get_user_pages;
> +	}
> +
> +	/* pages are no longer needed */
> +	kfree(pages);
> +	pages = NULL;
> +
> +	sgt->nents = dma_map_sg(buf->dev, sgt->sgl, sgt->orig_nents,
> +		buf->dma_dir);
> +	if (sgt->nents<= 0) {
> +		printk(KERN_ERR "failed to map scatterlist\n");
> +		ret = -EIO;
> +		goto fail_sgt;
>   	}
>
> +	contig_size = vb2_dc_get_contiguous_size(sgt);
> +	if (contig_size<  size) {
> +		printk(KERN_ERR "contiguous mapping is too small %lu/%lu\n",
> +			contig_size, size);
> +		ret = -EFAULT;
> +		goto fail_map_sg;
> +	}
> +
> +	buf->dma_addr = sg_dma_address(sgt->sgl);
>   	buf->size = size;
> -	buf->dma_addr = dma_addr;
> -	buf->vma = vma;
> +	buf->dma_sgt = sgt;
>
>   	return buf;
> -}
>
> -static void vb2_dc_put_userptr(void *mem_priv)
> -{
> -	struct vb2_dc_buf *buf = mem_priv;
> +fail_map_sg:
> +	dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
>
> -	if (!buf)
> -		return;
> +fail_sgt:
> +	if (!vma_is_io(buf->vma))
> +		vb2_dc_sgt_foreach_page(sgt, put_page);
> +	vb2_dc_release_sgtable(sgt);
> +
> +fail_get_user_pages:
> +	if (pages&&  !vma_is_io(buf->vma))
> +		while (n_pages)
> +			put_page(pages[--n_pages]);
>
> +fail_vma:
>   	vb2_put_vma(buf->vma);
> +
> +fail_pages:
> +	kfree(pages); /* kfree is NULL-proof */
> +
> +fail_buf:
>   	kfree(buf);
> +
> +	return ERR_PTR(ret);
>   }
>
>   /*********************************************/

Re: [PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Tomasz Stanislawski]

Hi Subash,
Could you provide a detailed description of a test case
that causes a failure of vb2_dc_pages_to_sgt?

Regards,
Tomasz Stanislawski

Re: [PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Subash Patel]

Hi Thomasz,

I have extended the MFC-FIMC testcase posted by Kamil sometime ago to 
sanity test the UMM patches. This test is multi-threaded(further 
explanation for developers who may not have seen it yet), where thread 
one parses the encoded stream and feeds into the codec  IP driver(aka 
MFC driver). Second thread will dequeue the buffer from MFC driver 
(DMA_BUF export) and queues it into a CSC IP(aka FIMC) driver(DMA_BUF 
import). Third thread dequeues the frame from FIMC driver and either 
pushes it into LCD driver for display or dumps to a flat file for analysis.

MFC driver exports the fd's and FIMC driver imports and attaches it. 
During FIMC QBUF (thats when the attach and map happens), it is observed 
that in the function vb2_dc_map_dmabuf() call to 
vb2_dc_get_contiguous_size() fails. This is because contig_size < 
buf->size. contig_size is calculated from the SGT which we would have 
constructed in the function vb2_dc_pages_to_sgt().

Let me know if you need more details.

Regards,
Subash

On 05/07/2012 08:41 PM, Tomasz Stanislawski wrote:
> Hi Subash,
> Could you provide a detailed description of a test case
> that causes a failure of vb2_dc_pages_to_sgt?
>
> Regards,
> Tomasz Stanislawski

Re: [PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Laurent Pinchart]

Hi Subash,

On Monday 07 May 2012 20:08:25 Subash Patel wrote:
> Hello Thomasz, Laurent,
> 
> I found an issue in the function vb2_dc_pages_to_sgt() below. I saw that
> during the attach, the size of the SGT and size requested mis-matched
> (by atleast 8k bytes). Hence I made a small correction to the code as
> below. I could then attach the importer properly.

Thank you for the report.

Could you print the content of the sglist (number of chunks and size of each 
chunk) before and after your modifications, as well as the values of n_pages, 
offset and size ?

> On 04/20/2012 08:15 PM, Tomasz Stanislawski wrote:

[snip]

> > +static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages,
> > +	unsigned int n_pages, unsigned long offset, unsigned long size)
> > +{
> > +	struct sg_table *sgt;
> > +	unsigned int chunks;
> > +	unsigned int i;
> > +	unsigned int cur_page;
> > +	int ret;
> > +	struct scatterlist *s;
> > +
> > +	sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
> > +	if (!sgt)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	/* compute number of chunks */
> > +	chunks = 1;
> > +	for (i = 1; i<  n_pages; ++i)
> > +		if (pages[i] != pages[i - 1] + 1)
> > +			++chunks;
> > +
> > +	ret = sg_alloc_table(sgt, chunks, GFP_KERNEL);
> > +	if (ret) {
> > +		kfree(sgt);
> > +		return ERR_PTR(-ENOMEM);
> > +	}
> > +
> > +	/* merging chunks and putting them into the scatterlist */
> > +	cur_page = 0;
> > +	for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
> > +		unsigned long chunk_size;
> > +		unsigned int j;
> 
> 		size = PAGE_SIZE;
> 
> > +
> > +		for (j = cur_page + 1; j<  n_pages; ++j)
> 
> 		for (j = cur_page + 1; j < n_pages; ++j) {
> 
> > +			if (pages[j] != pages[j - 1] + 1)
> > +				break;
> 
> 			size += PAGE
> 		}
> 
> > +
> > +		chunk_size = ((j - cur_page)<<  PAGE_SHIFT) - offset;
> > +		sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
> 
> 		[DELETE] size -= chunk_size;
> 
> > +		offset = 0;
> > +		cur_page = j;
> > +	}
> > +
> > +	return sgt;
> > +}

-- 
Regards,

Laurent Pinchart

Re: [PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Subash Patel]

Hi Laurent,

On 05/08/2012 02:44 PM, Laurent Pinchart wrote:
> Hi Subash,
>
> On Monday 07 May 2012 20:08:25 Subash Patel wrote:
>> Hello Thomasz, Laurent,
>>
>> I found an issue in the function vb2_dc_pages_to_sgt() below. I saw that
>> during the attach, the size of the SGT and size requested mis-matched
>> (by atleast 8k bytes). Hence I made a small correction to the code as
>> below. I could then attach the importer properly.
>
> Thank you for the report.
>
> Could you print the content of the sglist (number of chunks and size of each
> chunk) before and after your modifications, as well as the values of n_pages,
> offset and size ?
I will put back all the printk's and generate this. As of now, my setup 
has changed and will do this when I get sometime.
>
>> On 04/20/2012 08:15 PM, Tomasz Stanislawski wrote:
>
> [snip]
>
>>> +static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages,
>>> +	unsigned int n_pages, unsigned long offset, unsigned long size)
>>> +{
>>> +	struct sg_table *sgt;
>>> +	unsigned int chunks;
>>> +	unsigned int i;
>>> +	unsigned int cur_page;
>>> +	int ret;
>>> +	struct scatterlist *s;
>>> +
>>> +	sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
>>> +	if (!sgt)
>>> +		return ERR_PTR(-ENOMEM);
>>> +
>>> +	/* compute number of chunks */
>>> +	chunks = 1;
>>> +	for (i = 1; i<   n_pages; ++i)
>>> +		if (pages[i] != pages[i - 1] + 1)
>>> +			++chunks;
>>> +
>>> +	ret = sg_alloc_table(sgt, chunks, GFP_KERNEL);
>>> +	if (ret) {
>>> +		kfree(sgt);
>>> +		return ERR_PTR(-ENOMEM);
>>> +	}
>>> +
>>> +	/* merging chunks and putting them into the scatterlist */
>>> +	cur_page = 0;
>>> +	for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
>>> +		unsigned long chunk_size;
>>> +		unsigned int j;
>>
>> 		size = PAGE_SIZE;
>>
>>> +
>>> +		for (j = cur_page + 1; j<   n_pages; ++j)
>>
>> 		for (j = cur_page + 1; j<  n_pages; ++j) {
>>
>>> +			if (pages[j] != pages[j - 1] + 1)
>>> +				break;
>>
>> 			size += PAGE
>> 		}
>>
>>> +
>>> +		chunk_size = ((j - cur_page)<<   PAGE_SHIFT) - offset;
>>> +		sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
>>
>> 		[DELETE] size -= chunk_size;
>>
>>> +		offset = 0;
>>> +		cur_page = j;
>>> +	}
>>> +
>>> +	return sgt;
>>> +}
>
Regards,
Subash

Re: [PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Subash Patel]

[-- Attachment #1: Type: text/plain, Size: 2523 bytes --]

Hello Tomasz, Laurent,

I have printed some logs during the dmabuf export and attach for the SGT 
issue below. Please find it in the attachment. I hope it will be useful.

Regards,
Subash

On 05/08/2012 04:45 PM, Subash Patel wrote:
> Hi Laurent,
>
> On 05/08/2012 02:44 PM, Laurent Pinchart wrote:
>> Hi Subash,
>>
>> On Monday 07 May 2012 20:08:25 Subash Patel wrote:
>>> Hello Thomasz, Laurent,
>>>
>>> I found an issue in the function vb2_dc_pages_to_sgt() below. I saw that
>>> during the attach, the size of the SGT and size requested mis-matched
>>> (by atleast 8k bytes). Hence I made a small correction to the code as
>>> below. I could then attach the importer properly.
>>
>> Thank you for the report.
>>
>> Could you print the content of the sglist (number of chunks and size
>> of each
>> chunk) before and after your modifications, as well as the values of
>> n_pages,
>> offset and size ?
> I will put back all the printk's and generate this. As of now, my setup
> has changed and will do this when I get sometime.
>>
>>> On 04/20/2012 08:15 PM, Tomasz Stanislawski wrote:
>>
>> [snip]
>>
>>>> +static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages,
>>>> + unsigned int n_pages, unsigned long offset, unsigned long size)
>>>> +{
>>>> + struct sg_table *sgt;
>>>> + unsigned int chunks;
>>>> + unsigned int i;
>>>> + unsigned int cur_page;
>>>> + int ret;
>>>> + struct scatterlist *s;
>>>> +
>>>> + sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
>>>> + if (!sgt)
>>>> + return ERR_PTR(-ENOMEM);
>>>> +
>>>> + /* compute number of chunks */
>>>> + chunks = 1;
>>>> + for (i = 1; i< n_pages; ++i)
>>>> + if (pages[i] != pages[i - 1] + 1)
>>>> + ++chunks;
>>>> +
>>>> + ret = sg_alloc_table(sgt, chunks, GFP_KERNEL);
>>>> + if (ret) {
>>>> + kfree(sgt);
>>>> + return ERR_PTR(-ENOMEM);
>>>> + }
>>>> +
>>>> + /* merging chunks and putting them into the scatterlist */
>>>> + cur_page = 0;
>>>> + for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
>>>> + unsigned long chunk_size;
>>>> + unsigned int j;
>>>
>>> size = PAGE_SIZE;
>>>
>>>> +
>>>> + for (j = cur_page + 1; j< n_pages; ++j)
>>>
>>> for (j = cur_page + 1; j< n_pages; ++j) {
>>>
>>>> + if (pages[j] != pages[j - 1] + 1)
>>>> + break;
>>>
>>> size += PAGE
>>> }
>>>
>>>> +
>>>> + chunk_size = ((j - cur_page)<< PAGE_SHIFT) - offset;
>>>> + sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
>>>
>>> [DELETE] size -= chunk_size;
>>>
>>>> + offset = 0;
>>>> + cur_page = j;
>>>> + }
>>>> +
>>>> + return sgt;
>>>> +}
>>
> Regards,
> Subash

[-- Attachment #2: vb2_log --]
[-- Type: text/plain, Size: 14436 bytes --]

[  178.545000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  178.545000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.550000] vb2_dc_pages_to_sgt():84 offset=0
[  178.555000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  178.560000] vb2_dc_pages_to_sgt():89 size=4294836224
[  178.565000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  178.570000] vb2_dc_pages_to_sgt():83 cur_page=32
[  178.575000] vb2_dc_pages_to_sgt():84 offset=0
[  178.580000] vb2_dc_pages_to_sgt():86 chunk_size=262144
[  178.585000] vb2_dc_pages_to_sgt():89 size=4294574080
[  178.590000] vb2_dc_pages_to_sgt() sgt->orig_nents=1
[  178.595000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.600000] vb2_dc_pages_to_sgt():84 offset=0
[  178.605000] vb2_dc_pages_to_sgt():86 chunk_size=8192
[  178.610000] vb2_dc_pages_to_sgt():89 size=4294959104
[  178.625000] vb2_dc_pages_to_sgt() sgt->orig_nents=1
[  178.625000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.630000] vb2_dc_pages_to_sgt():84 offset=0
[  178.635000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  178.640000] vb2_dc_pages_to_sgt():89 size=4294836224
[  178.645000] vb2_dc_pages_to_sgt() sgt->orig_nents=1
[  178.650000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.655000] vb2_dc_pages_to_sgt():84 offset=0
[  178.660000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  178.665000] vb2_dc_pages_to_sgt():89 size=4294836224
[  178.670000] vb2_dc_mmap: mapped dma addr 0x20060000 at 0xb6e01000, size 131072
[  178.670000] vb2_dc_mmap: mapped dma addr 0x20080000 at 0xb6de1000, size 131072
[  178.680000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  178.685000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.690000] vb2_dc_pages_to_sgt():84 offset=0
[  178.695000] vb2_dc_pages_to_sgt():86 chunk_size=4096
[  178.700000] vb2_dc_pages_to_sgt():89 size=4294963200
[  178.705000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  178.710000] vb2_dc_pages_to_sgt():83 cur_page=1
[  178.715000] vb2_dc_pages_to_sgt():84 offset=0
[  178.715000] vb2_dc_pages_to_sgt():86 chunk_size=8192
[  178.720000] vb2_dc_pages_to_sgt():89 size=4294955008
[  178.725000] vb2_dc_pages_to_sgt() sgt->orig_nents=1
[  178.730000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.735000] vb2_dc_pages_to_sgt():84 offset=0
[  178.740000] vb2_dc_pages_to_sgt():86 chunk_size=8192
[  178.745000] vb2_dc_pages_to_sgt():89 size=4294959104
[  178.750000] vb2_dc_pages_to_sgt() sgt->orig_nents=1
[  178.755000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.760000] vb2_dc_pages_to_sgt():84 offset=0
[  178.765000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  178.770000] vb2_dc_pages_to_sgt():89 size=4294836224
[  178.780000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  178.780000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.785000] vb2_dc_pages_to_sgt():84 offset=0
[  178.790000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  178.795000] vb2_dc_pages_to_sgt():89 size=4294901760
[  178.800000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  178.805000] vb2_dc_pages_to_sgt():83 cur_page=16
[  178.810000] vb2_dc_pages_to_sgt():84 offset=0
[  178.815000] vb2_dc_pages_to_sgt():86 chunk_size=393216
[  178.820000] vb2_dc_pages_to_sgt():89 size=4294508544
[  178.825000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  178.830000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.835000] vb2_dc_pages_to_sgt():84 offset=0
[  178.840000] vb2_dc_pages_to_sgt():86 chunk_size=32768
[  178.845000] vb2_dc_pages_to_sgt():89 size=4294934528
[  178.850000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  178.855000] vb2_dc_pages_to_sgt():83 cur_page=8
[  178.855000] vb2_dc_pages_to_sgt():84 offset=0
[  178.860000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  178.865000] vb2_dc_pages_to_sgt():89 size=4294868992
[  178.870000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  178.875000] vb2_dc_pages_to_sgt():83 cur_page=24
[  178.880000] vb2_dc_pages_to_sgt():84 offset=0
[  178.885000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  178.890000] vb2_dc_pages_to_sgt():89 size=4294737920
[  178.895000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  178.900000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.905000] vb2_dc_pages_to_sgt():84 offset=0
[  178.910000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  178.915000] vb2_dc_pages_to_sgt():89 size=4294901760
[  178.920000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  178.925000] vb2_dc_pages_to_sgt():83 cur_page=16
[  178.930000] vb2_dc_pages_to_sgt():84 offset=0
[  178.935000] vb2_dc_pages_to_sgt():86 chunk_size=393216
[  178.940000] vb2_dc_pages_to_sgt():89 size=4294508544
[  178.945000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  178.950000] vb2_dc_pages_to_sgt():83 cur_page=0
[  178.955000] vb2_dc_pages_to_sgt():84 offset=0
[  178.960000] vb2_dc_pages_to_sgt():86 chunk_size=32768
[  178.965000] vb2_dc_pages_to_sgt():89 size=4294934528
[  178.970000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  178.975000] vb2_dc_pages_to_sgt():83 cur_page=8
[  178.975000] vb2_dc_pages_to_sgt():84 offset=0
[  178.980000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  178.985000] vb2_dc_pages_to_sgt():89 size=4294868992
[  178.990000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  178.995000] vb2_dc_pages_to_sgt():83 cur_page=24
[  179.000000] vb2_dc_pages_to_sgt():84 offset=0
[  179.005000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  179.010000] vb2_dc_pages_to_sgt():89 size=4294737920
[  179.015000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.020000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.025000] vb2_dc_pages_to_sgt():84 offset=0
[  179.030000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.035000] vb2_dc_pages_to_sgt():89 size=4294901760
[  179.040000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.045000] vb2_dc_pages_to_sgt():83 cur_page=16
[  179.050000] vb2_dc_pages_to_sgt():84 offset=0
[  179.055000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  179.060000] vb2_dc_pages_to_sgt():89 size=4294770688
[  179.065000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.070000] vb2_dc_pages_to_sgt():83 cur_page=48
[  179.075000] vb2_dc_pages_to_sgt():84 offset=0
[  179.080000] vb2_dc_pages_to_sgt():86 chunk_size=262144
[  179.085000] vb2_dc_pages_to_sgt():89 size=4294508544
[  179.090000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.095000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.100000] vb2_dc_pages_to_sgt():84 offset=0
[  179.100000] vb2_dc_pages_to_sgt():86 chunk_size=32768
[  179.105000] vb2_dc_pages_to_sgt():89 size=4294934528
[  179.110000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.115000] vb2_dc_pages_to_sgt():83 cur_page=8
[  179.120000] vb2_dc_pages_to_sgt():84 offset=0
[  179.125000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.130000] vb2_dc_pages_to_sgt():89 size=4294868992
[  179.135000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.140000] vb2_dc_pages_to_sgt():83 cur_page=24
[  179.145000] vb2_dc_pages_to_sgt():84 offset=0
[  179.150000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  179.155000] vb2_dc_pages_to_sgt():89 size=4294737920
[  179.160000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  179.165000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.170000] vb2_dc_pages_to_sgt():84 offset=0
[  179.175000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.180000] vb2_dc_pages_to_sgt():89 size=4294901760
[  179.185000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  179.190000] vb2_dc_pages_to_sgt():83 cur_page=16
[  179.195000] vb2_dc_pages_to_sgt():84 offset=0
[  179.200000] vb2_dc_pages_to_sgt():86 chunk_size=393216
[  179.205000] vb2_dc_pages_to_sgt():89 size=4294508544
[  179.210000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.215000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.220000] vb2_dc_pages_to_sgt():84 offset=0
[  179.220000] vb2_dc_pages_to_sgt():86 chunk_size=32768
[  179.225000] vb2_dc_pages_to_sgt():89 size=4294934528
[  179.230000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.235000] vb2_dc_pages_to_sgt():83 cur_page=8
[  179.240000] vb2_dc_pages_to_sgt():84 offset=0
[  179.245000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.250000] vb2_dc_pages_to_sgt():89 size=4294868992
[  179.255000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.260000] vb2_dc_pages_to_sgt():83 cur_page=24
[  179.265000] vb2_dc_pages_to_sgt():84 offset=0
[  179.270000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  179.275000] vb2_dc_pages_to_sgt():89 size=4294737920
[  179.280000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.285000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.290000] vb2_dc_pages_to_sgt():84 offset=0
[  179.295000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.300000] vb2_dc_pages_to_sgt():89 size=4294901760
[  179.305000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.310000] vb2_dc_pages_to_sgt():83 cur_page=16
[  179.315000] vb2_dc_pages_to_sgt():84 offset=0
[  179.320000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  179.325000] vb2_dc_pages_to_sgt():89 size=4294770688
[  179.330000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.335000] vb2_dc_pages_to_sgt():83 cur_page=48
[  179.340000] vb2_dc_pages_to_sgt():84 offset=0
[  179.340000] vb2_dc_pages_to_sgt():86 chunk_size=262144
[  179.350000] vb2_dc_pages_to_sgt():89 size=4294508544
[  179.355000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.355000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.360000] vb2_dc_pages_to_sgt():84 offset=0
[  179.365000] vb2_dc_pages_to_sgt():86 chunk_size=32768
[  179.370000] vb2_dc_pages_to_sgt():89 size=4294934528
[  179.375000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.380000] vb2_dc_pages_to_sgt():83 cur_page=8
[  179.385000] vb2_dc_pages_to_sgt():84 offset=0
[  179.390000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.395000] vb2_dc_pages_to_sgt():89 size=4294868992
[  179.400000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.405000] vb2_dc_pages_to_sgt():83 cur_page=24
[  179.410000] vb2_dc_pages_to_sgt():84 offset=0
[  179.415000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  179.420000] vb2_dc_pages_to_sgt():89 size=4294737920
[  179.425000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  179.430000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.435000] vb2_dc_pages_to_sgt():84 offset=0
[  179.440000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.445000] vb2_dc_pages_to_sgt():89 size=4294901760
[  179.450000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  179.455000] vb2_dc_pages_to_sgt():83 cur_page=16
[  179.460000] vb2_dc_pages_to_sgt():84 offset=0
[  179.460000] vb2_dc_pages_to_sgt():86 chunk_size=393216
[  179.470000] vb2_dc_pages_to_sgt():89 size=4294508544
[  179.475000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.475000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.480000] vb2_dc_pages_to_sgt():84 offset=0
[  179.485000] vb2_dc_pages_to_sgt():86 chunk_size=32768
[  179.490000] vb2_dc_pages_to_sgt():89 size=4294934528
[  179.495000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.500000] vb2_dc_pages_to_sgt():83 cur_page=8
[  179.505000] vb2_dc_pages_to_sgt():84 offset=0
[  179.510000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.515000] vb2_dc_pages_to_sgt():89 size=4294868992
[  179.520000] vb2_dc_pages_to_sgt() sgt->orig_nents=3
[  179.525000] vb2_dc_pages_to_sgt():83 cur_page=24
[  179.530000] vb2_dc_pages_to_sgt():84 offset=0
[  179.535000] vb2_dc_pages_to_sgt():86 chunk_size=131072
[  179.540000] vb2_dc_pages_to_sgt():89 size=4294737920
[  179.545000] mmc0: Too large timeout requested for CMD25!
[  179.545000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  179.550000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.555000] mmc0: Too large timeout requested for CMD25!
[  179.555000] vb2_dc_pages_to_sgt():84 offset=0
[  179.560000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.565000] mmc0: Too large timeout requested for CMD25!
[  179.565000] vb2_dc_pages_to_sgt():89 size=4294901760
[  179.570000] vb2_dc_pages_to_sgt() sgt->orig_nents=2
[  179.575000] vb2_dc_pages_to_sgt():83 cur_page=16
[  179.580000] vb2_dc_pages_to_sgt():84 offset=0
[  179.580000] vb2_dc_pages_to_sgt():86 chunk_size=262144
[  179.590000] vb2_dc_pages_to_sgt():89 size=4294639616
[  179.595000] vb2_dc_mmap: mapped dma addr 0x40000000 at 0xb6d71000, size 458752
[  179.595000] vb2_dc_mmap: mapped dma addr 0x20100000 at 0xb6d39000, size 229376
[  179.595000] vb2_dc_mmap: mapped dma addr 0x40080000 at 0xb6cc9000, size 458752
[  179.595000] vb2_dc_mmap: mapped dma addr 0x20140000 at 0xb6c91000, size 229376
[  179.595000] vb2_dc_mmap: mapped dma addr 0x40100000 at 0xb6c21000, size 458752
[  179.595000] vb2_dc_mmap: mapped dma addr 0x20180000 at 0xb6be9000, size 229376
[  179.595000] vb2_dc_mmap: mapped dma addr 0x40180000 at 0xb6b79000, size 458752
[  179.595000] vb2_dc_mmap: mapped dma addr 0x201c0000 at 0xb6b41000, size 229376
[  179.595000] vb2_dc_mmap: mapped dma addr 0x40200000 at 0xb6ad1000, size 458752
[  179.595000] vb2_dc_mmap: mapped dma addr 0x20200000 at 0xb6a99000, size 229376
[  179.600000] vb2_dc_mmap: mapped dma addr 0x40280000 at 0xb6a29000, size 458752
[  179.600000] vb2_dc_mmap: mapped dma addr 0x20240000 at 0xb69f1000, size 229376
[  179.600000] vb2_dc_pages_to_sgt() sgt->orig_nents=4
[  179.605000] vb2_dc_pages_to_sgt():83 cur_page=0
[  179.610000] vb2_dc_pages_to_sgt():84 offset=0
[  179.615000] vb2_dc_pages_to_sgt():86 chunk_size=8192
[  179.620000] vb2_dc_pages_to_sgt():89 size=4294959104
[  179.625000] vb2_dc_pages_to_sgt() sgt->orig_nents=4
[  179.630000] vb2_dc_pages_to_sgt():83 cur_page=2
[  179.635000] vb2_dc_pages_to_sgt():84 offset=0
[  179.635000] vb2_dc_pages_to_sgt():86 chunk_size=16384
[  179.640000] vb2_dc_pages_to_sgt():89 size=4294942720
[  179.645000] vb2_dc_pages_to_sgt() sgt->orig_nents=4
[  179.650000] vb2_dc_pages_to_sgt():83 cur_page=6
[  179.655000] vb2_dc_pages_to_sgt():84 offset=0
[  179.660000] vb2_dc_pages_to_sgt():86 chunk_size=65536
[  179.665000] vb2_dc_pages_to_sgt():89 size=4294877184
[  179.670000] vb2_dc_pages_to_sgt() sgt->orig_nents=4
[  179.675000] vb2_dc_pages_to_sgt():83 cur_page=22
[  179.680000] vb2_dc_pages_to_sgt():84 offset=0
[  179.685000] vb2_dc_pages_to_sgt():86 chunk_size=524288
[  179.690000] vb2_dc_pages_to_sgt():89 size=4294352896
[  179.695000] vb2_dc_mmap: mapped dma addr 0x20000000 at 0xb695b000, size 614400
[  180.000000] mmc0: Too large timeout requested for CMD25!
[  180.075000] Entering vb2_dc_get_contiguous_size()
[  180.080000] sg_dma_address=0x20100000, sg_dma_len=393216
[  180.085000] expected=0x20160000
[  180.090000] Leaving vb2_dc_get_contiguous_size()
[  180.095000] vb2_dc_map_dmabuf():671contig_size=393216, buf->size=430080
[  180.100000] contiguous chunk is too small 393216/430080 b

Re: [PATCHv5 08/13] v4l: vb2-dma-contig: add support for scatterlist in userptr mode

[Tomasz Stanislawski]

Hi Subash,
Could you post the code of vb2_dc_pages_to_sgt with all printk in it.
It will help us avoid guessing where and what is debugged in the log.

Moreover, I found a line 'size=4294836224' in the log.
It means that size is equal to -131072 (!?!) or there are some invalid
conversions in printk.

Are you suze that you do not pass size = 0 as the function argument?

Notice that earlier versions of dmabuf-for-vb2 patches has offset2
argument instead of size. It was the offset at the end of the buffer.
In (I guess) 95% of cases this offset was 0.

Could you provide only function arguments that causes the failure?
I mean pages array + size (I assume that offset is zero for your test).

Having the arguments we could reproduce that bug.

Regards,
Tomasz Stanislawski





On 05/09/2012 08:46 AM, Subash Patel wrote:
> Hello Tomasz, Laurent,
> 
> I have printed some logs during the dmabuf export and attach for the SGT issue below. Please find it in the attachment. I hope
> it will be useful.
> 
> Regards,
> Subash
> 
> On 05/08/2012 04:45 PM, Subash Patel wrote:
>> Hi Laurent,
>>
>> On 05/08/2012 02:44 PM, Laurent Pinchart wrote:
>>> Hi Subash,
>>>
>>> On Monday 07 May 2012 20:08:25 Subash Patel wrote:
>>>> Hello Thomasz, Laurent,
>>>>
>>>> I found an issue in the function vb2_dc_pages_to_sgt() below. I saw that
>>>> during the attach, the size of the SGT and size requested mis-matched
>>>> (by atleast 8k bytes). Hence I made a small correction to the code as
>>>> below. I could then attach the importer properly.
>>>
>>> Thank you for the report.
>>>
>>> Could you print the content of the sglist (number of chunks and size
>>> of each
>>> chunk) before and after your modifications, as well as the values of
>>> n_pages,
>>> offset and size ?
>> I will put back all the printk's and generate this. As of now, my setup
>> has changed and will do this when I get sometime.
>>>
>>>> On 04/20/2012 08:15 PM, Tomasz Stanislawski wrote:
>>>
>>> [snip]
>>>
>>>>> +static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages,
>>>>> + unsigned int n_pages, unsigned long offset, unsigned long size)
>>>>> +{
>>>>> + struct sg_table *sgt;
>>>>> + unsigned int chunks;
>>>>> + unsigned int i;
>>>>> + unsigned int cur_page;
>>>>> + int ret;
>>>>> + struct scatterlist *s;
>>>>> +
>>>>> + sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
>>>>> + if (!sgt)
>>>>> + return ERR_PTR(-ENOMEM);
>>>>> +
>>>>> + /* compute number of chunks */
>>>>> + chunks = 1;
>>>>> + for (i = 1; i< n_pages; ++i)
>>>>> + if (pages[i] != pages[i - 1] + 1)
>>>>> + ++chunks;
>>>>> +
>>>>> + ret = sg_alloc_table(sgt, chunks, GFP_KERNEL);
>>>>> + if (ret) {
>>>>> + kfree(sgt);
>>>>> + return ERR_PTR(-ENOMEM);
>>>>> + }
>>>>> +
>>>>> + /* merging chunks and putting them into the scatterlist */
>>>>> + cur_page = 0;
>>>>> + for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
>>>>> + unsigned long chunk_size;
>>>>> + unsigned int j;
>>>>
>>>> size = PAGE_SIZE;
>>>>
>>>>> +
>>>>> + for (j = cur_page + 1; j< n_pages; ++j)
>>>>
>>>> for (j = cur_page + 1; j< n_pages; ++j) {
>>>>
>>>>> + if (pages[j] != pages[j - 1] + 1)
>>>>> + break;
>>>>
>>>> size += PAGE
>>>> }
>>>>
>>>>> +
>>>>> + chunk_size = ((j - cur_page)<< PAGE_SHIFT) - offset;
>>>>> + sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
>>>>
>>>> [DELETE] size -= chunk_size;
>>>>
>>>>> + offset = 0;
>>>>> + cur_page = j;
>>>>> + }
>>>>> +
>>>>> + return sgt;
>>>>> +}
>>>
>> Regards,
>> Subash